diff --git a/.rubocop.yml b/.rubocop.yml
index 19cc045..9740508 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -7,8 +7,13 @@ AllCops:
 
 Layout/DotPosition:
   EnforcedStyle: trailing
+Layout/ElseAlignment:
+  Enabled: false
+Layout/EndAlignment:
+  Enabled: false
 Layout/HashAlignment:
   Enabled: false
+
 Layout/MultilineMethodCallBraceLayout:
   EnforcedStyle: new_line
 Layout/MultilineMethodCallIndentation:
diff --git a/spec/year_2023/day_03_input b/spec/year_2023/day_03_input
new file mode 100644
index 0000000..cda5bac
--- /dev/null
+++ b/spec/year_2023/day_03_input
@@ -0,0 +1,140 @@
+.........232.633.......................803..........................361................192............539.................973.221...340.....
+.............*..............#.....256.#.........329....................*313............*.......766.......*..........472..-...........+..249.
+670-..@.......181......814..865.........968......@.......605....128.............%......798.638...+....776...........*......%...........*....
+.......563........741....*..........&.....-...............*........*....815*....921...........*..............428.219..993.584...990.431.....
+.........................466.971..815...&....634.197.%...887....114.........521.........&..796.......-.......+..........*......*............
+................713.546......*........941......*..*..837............903...............910.........988....61..........&..946..240......697...
+........563........*....707-..895...........223..160......618..........*..................................&...61...603............495.=.....
+..........$............................+633............................697.910.....@70..................................497......*..........
+...568..........+832......@.......551............#863...324*......................................837......701..740.................72......
+.....*.98..................245....#.........&...............145................#...832.......580.....*.......$../.....432..........*........
+..315....../......4.......................174......*971............76.......472..............*.......66...................260.....348.......
+.......179.908.....%.......-....-108.726........654......422.................................501.644....279.....&.....528*..................
+........*.................913..........*.639*............-...........-131..5.....%......................*.......228.........900..148........
+......665..........220.......................561...........................*...237..576.381.........../.......................*.............
+771................*.................416.................996.799........441..........*..=..........355...........570.481*422..798...........
+....+924..#462..420..659@.404.........#...................*..*......*..........233.........................955...%..........................
+..........................................265.........86..43..1.398..624......*........896.53.855............/........301...............#...
+...............688.................#..614*..............*........#............103.486...@....*....+........................672.725....508...
+...........993...=.....906.124....92.............208@.626...298.....................*..........810........428*461..619........*.............
+590*......*........636..*..*...........683..................@.....*128...524...../...507..@636........................=...........991.....52
+....61.993............*....627...=796..*.......................841..........#....105...........313......=...................555...#.........
+715........625..963.194.................505..841......&442.............108*....................=.........58.......450..........*............
+............*....*..........343.138*560.......-............................561..........*53.................$........#.327......766....234..
+.....-...276....370..........%............913..................16.825.............%..111.....561..........446...............................
+.....372...............................@............@..........././....*8.......136......758....&..349.................666.....*............
+.........340..639............214......364..31&.......440..644$......577....................&......*.....................#...382.............
+........*.......................*..........................................175..........84........931..692.......................*..........
+.......860..........@..........400............235.....797.................*...............*...863................683/....778..367.79........
+..................192.....%...........897..............*.....320*634......................32..............556...........................$...
+...........783...........475.............*.781......875..891...........867......322...............8..........*...938..318.462*........&..620
+....#.......*....$293.................330.....*............*...........*.....26*.......668.205.......32.%....975.....#........750...25......
+..521......388.........116.....33.............2...........519..717..859..............&....*....*881.*...109...............828...............
+................................*...927.........................*.....................240....66.....27.......482.227*...................#968
+...$479...........91*...%.......598........102../.........615.....184..@......456.385....................+.....*.....476...13+...391........
+........................526..................+...90..............*....500.......$....*.....14......*......206.57............................
+.........53&...134*...........%784....=................775.692.88..........873......115..9.*....937.242..................729...342......344.
+....*568.....#.....................-..140...=.............*..................*..............521................185......*......*............
+.462..........331...$......337...90........829.....$.........262=.....376..787.........*352...................*..........227..413....518....
+......&............796.698...@.................346..277....=.........*............%.918......902.....327.....120....320...............*.....
+....902.....488..%...............................*........150.688...822.........721...........*......................*.............*3.445...
+...........*....132...........71..880.........770.....150..................................674.............924........746.......403.........
+.....929...771..................*..................$.....*..110....63..................847.............423...-....651.......................
+................./......729...927..867..........577...763...*........*..55.....320*......../..674.962..............*.............421........
+.../...........707.........*...........222.................301....702....*.........943...431..+....#....59.600..756...593..352..=......*579.
+.965...607............669.406.704........*..............#......*......720.................................*..........@.......@..............
+...........333.........*......*..........839.............449...210.........219........=84...842.............................................
+.......582...-..........350.831..394.835.....184...........................*.....676........*............755.........22.....................
+..710.....&............................#........+.....................86.889..............86..625..........*...........*......195.547.......
+......549....945.601.........*.......+......975..............285.................743.........*............433..........619..........*....675
+.........+.............204..161.......493..*.......896...576..*........328...............902.819....362..........373..............854..-....
+.......................*..........272.......812....../..*.....933..447.....950...124.....*.............*....990....+..$172....139.......530.
+27...$....844.486.....810.826........+...................880.......=........=...*.....359....242#..432..206....................*............
+.....519...+....*.........&.....................805..66.......................@.......................*.........859.........943.............
+742............116..........*421..-984.......=...*..#....+...559....*566...790........$......372.307...180.....*...................532......
+...*.....................135................88.417....576......+......................138......*....-.......314........776...........*......
+.670..................................893.........................565..985......833..........369..=....#372........842......868...221.......
+.......168..128....500..........962..*....31........143.....897*..@...*..............727..........42.........................*........24-...
+..382.*.....*..................*....593................................414..165...........................179+..42....$.=.......=...........
+....*..468..362......39.........802....................339.................*..................240............../...257...386.262..556.......
+...852..............*....670...............872........../.........480.....945..983*604....997*..........182......................*..........
+.........916.....800...*..*........#......*.......165...............#..........................%....927...*.....................55.....#....
+.........*............521.394.......142...672.967..........107...........785.208.....-...&....614....@...386.975...................923..273.
+...146..70....................................*....177....*........550......*.....606...430....................*....35......=.........*.....
+.....*.....=..707..157*334......675*....=..719......*.....762.....+.....960.................................343....*.......498.........291..
+..654....592.....*..................54.500...........772.................*.....................252....689...........357........778.273......
+..............455....$.........381*...........*117................388.386...........258/......*...................*..............*....*.....
+.....................948...........914.....514.......476........../........975................274.....119.....-.56.94.....390...250.484.....
+......723........................................415....*451................*...2.......................*...115..............-..............
+..818*.................859.401*240...205...228...................757.102...954......#.............863.523...................................
+.........613.844.832..................*...-..................35.......*............989.....+........*.........381..............827.702......
+..........*....*...................592.............=456.....*...@.385...78..................233.....27...............49.574.....*.....=.....
+........230.311...326...617..585.........................798..699.%....=.....20........................687.....662.......*......246.........
+735..61..........*......*.....*.............361....................................=...................%........*.....171...380........786..
+.......*..%......378.624.........836*742...=...../...#...322......../...195.......634.....422..893*106.....-.....960.........*.....121*.....
+....969....738...............%..................919.78........685.773......*..............................654..=...........414..............
+...........................297...............=.........44.718...............718....841...446.....881+.../......825.870.........104..341.....
+.............663.292.............165....466...892.........@..........296..................*..............948.......*................*.......
+..748....*..........................$...*.........99...........707.....&.339...............483...............*....896.......&.....241.......
+...*..=...494....@..227.@821.............761.......*.............-.143...*......329...............24.......54.........202..588..............
+.481..203......37...............90..390........171..80...................857...$..........689+...+......=.......930...*.....................
+............#......*794..........*.*...........@..........233*503......................................62......%....%.14....*...........+...
+..438%....149...492...........842.......721..........................301.....................958../...............265....628.9.......813....
+.........................671*.....518......*.........903*974..120.....*..269...560....907....*...214............$........................961
+.............................22......*....740..................&.....825....*.*..../....+...612..................740..........307...467.....
+...............350......535.........665........138...........#....$......831..487..432...................................348..*.......*.....
+....32........................529.................*395......318...984...................492....*..........835...............$.735..333......
+....=.....136.................*.......................................&....779.848..*..*....486.......736....*..............................
+..........$......507..329.....189..............................745.....223.%.....*.552..888........+....*....53........415..................
+.....................=...................+..930....845..3..$..../...99........599................731.986..............-.......582....669....
+.367*969.........../.........132........13..*.....*.......420......@......442.........793.....................................*.....@.......
+..............997.908.148......+...........961.397....................9.......................144...736$...942.346.....970..72..........*794
+..608.13..993.+........$...........462...............539..560....637..#......208....896...5......*.......@...*..*..856*..............178....
+....*...$./................727..................787..=.....*.....*......593....*.....+...........736...191.609.774.................*........
+.....62.......325*.....372....*994../...........-..........513.853.907.........43...........*........................511-.850.......49..696.
+..........856.....651....*.........314...213..........+.............*..............%.....718.70...................*..........*.........=....
+....659*...*..........453..............................123.........921.......11=..32...............312....795..467.689.......760............
+............997................545.597.................................@.................$........*.........*...........................808.
+..565...............115.522.....*...........-..179...606.269.........885...733*.........857.857.252....510.842...518.......678........$.....
+....%..............*.....*.......420.426..92.....*......*......................447..........*............*...........995.....*.761.158......
+.......128.......178..495......%........*.......748.......927.411..........519..............430.......&..480...........*..667...*......+....
+.........*....................266..-846.625.807.......561*.........687.....*...*268....55=....../....60............%.556.......56......67...
+.........698..593+..485.......................*....................%......166..................174..............944.......591.....808.......
+.....698...........*....376......891...........951.............538.............563....472..........584*460...$............=.............492.
+....*...........716....*.........=.....238.297....................*........23*...*....*.....90..............668.............%...............
+...798.351....*.......720.513...............*....476..............312.&745....35..550.885...........343.........937.........435.........$...
+..........*....882.........#..............556....../..417...691...............................671......*...609...-.....424......*675.....650
+....9....900........*........867......................$....*..........975&..@.......897........$......905.....*.......$......122............
+.....&.......*...555.796....@...............&.............530..............229..............................585...................22........
+.......456.495.....................107...800............-.....683........................876......=....181*..............954.....$..........
+...774*..............643......437.....&..............310....-...&..............494*..265....%....320...............*.......*................
+........*13...........*..........$........................258................/.......*..................632.....677.227.922........#........
+.....778..............384....908........156%....533..............192..420.....861.771..=........553...........................860..370...309
+.............483..................................................*...................500..773....@.......900....................*......@...
+........249.%...............93*..................171...248...315...470..........169..................*198...*...........482.......771.......
+...267...*.....835/............6....459..252........&...*......*...............*......=.....496*..334.....493..............*................
+..........991...........191.........*........521/........661..514...............832....296....................$.650.....363......442........
+.....942...............*............58.................................390.....................$............865...-.........................
+..16*.........586...993....%..............255...55..........337...............334..............82..+....&..............490-..........5.381..
+.................*..........16.867...........*.&...35/.........*.427...........#..................877.768.......+.......................@...
+................110...413#........*104.....90..........623..433....=..*..462...........33.685.228................288.........513...721*.....
+........717.................#.344........................*...........970.................*.......#...953....546........162.............637..
+........*.................37...*.......740......331......564.....................556.................*.....*....843.......*.................
+..195............2*...........937......*.......-.......*..........=..255.349.....=.......*837.......342....411.*.......537...337.....791....
+........=..........641...............424.............24..........261....*.............667.....551&.............324..........%..........*....
+..330...841./465.......486......................&.......*996.........#..................................227...........&.........33.681..354.
+....@..................$........................455..........304.....542.#....64..624........./........*........716...245...166...*.........
+..........331*738...............249.................126..833...*..........913.................690....943..284..................*........938.
+.................................@....224...429....*......*.....195..................231..................*....857.............975..........
+............252..........71.599...................279...828............&......&.......+.................967...*............285.........798..
+.370.....&...*.............*.........640.............................898...746..134...........$.329.........768....279+.....=...840....*....
+...*...979.374..192..............370*..............964...970....................*..........436...*....410........................*....306...
+..................*.727...139*...........................-....689..819..498....982.....131.....566........................390....505........
+....................*.........84...973.......830..394.........*.........*...............*..........401.562..907.....405......$.......321....
+....#....455..*.....284............../.......*......-.722..124.......&...921...........303............./.......*652.....-........*....*.....
+.286.....*...775../.......274/....74...774.986.................96.469.......................335..526..................344..31.942.31...846..
+..........72.......582...................*..............#......*..........380&........570....../....*.........$....*........*...............
+......................................201....*648......838..253....101*.@................/..........606.....744..792.........396..-990..+609
+.938...............*..896..125*...........842...........................485...510............801.....................329.983................
+...*............963....*.......761..............................................*...927.........*...................*.....*........45.......
+....981................675.........676.............156.............30...........998............697......14..366....960...874..497........278
\ No newline at end of file
diff --git a/spec/year_2023/day_03_sample_one b/spec/year_2023/day_03_sample_one
new file mode 100644
index 0000000..624ea4f
--- /dev/null
+++ b/spec/year_2023/day_03_sample_one
@@ -0,0 +1,10 @@
+467..114..
+...*......
+..35..633.
+......#...
+617*......
+.....+.58.
+..592.....
+......755.
+...$.*....
+.664.598..
\ No newline at end of file
diff --git a/spec/year_2023/day_03_sample_one-bis b/spec/year_2023/day_03_sample_one-bis
new file mode 100644
index 0000000..b5574a7
--- /dev/null
+++ b/spec/year_2023/day_03_sample_one-bis
@@ -0,0 +1,12 @@
+12.......*..
++.........34
+.......-12..
+..78........
+..*....60...
+78..........
+.......23...
+....90*12...
+............
+2.2......12.
+.*.........*
+1.1.......56
\ No newline at end of file
diff --git a/spec/year_2023/day_03_sample_one-five b/spec/year_2023/day_03_sample_one-five
new file mode 100644
index 0000000..c58abb1
--- /dev/null
+++ b/spec/year_2023/day_03_sample_one-five
@@ -0,0 +1,3 @@
+........
+.24..4..
+......*.
\ No newline at end of file
diff --git a/spec/year_2023/day_03_sample_one-quad b/spec/year_2023/day_03_sample_one-quad
new file mode 100644
index 0000000..5bbebe9
--- /dev/null
+++ b/spec/year_2023/day_03_sample_one-quad
@@ -0,0 +1,8 @@
+..504.*
+*.102..
+.......
+.100...
+.......
+.*.....
+.......
+.200...
\ No newline at end of file
diff --git a/spec/year_2023/day_03_sample_one-seven b/spec/year_2023/day_03_sample_one-seven
new file mode 100644
index 0000000..dcbdb36
--- /dev/null
+++ b/spec/year_2023/day_03_sample_one-seven
@@ -0,0 +1,12 @@
+.......5......
+..7*..*.....4*
+...*13*......9
+.......15.....
+..............
+..............
+..............
+..............
+..............
+..............
+21............
+...*9.........
\ No newline at end of file
diff --git a/spec/year_2023/day_03_sample_one-six b/spec/year_2023/day_03_sample_one-six
new file mode 100644
index 0000000..58a7a49
--- /dev/null
+++ b/spec/year_2023/day_03_sample_one-six
@@ -0,0 +1,3 @@
+....................
+..-52..52-..52..52..
+..................-.
\ No newline at end of file
diff --git a/spec/year_2023/day_03_sample_one-ter b/spec/year_2023/day_03_sample_one-ter
new file mode 100644
index 0000000..5a0e3ec
--- /dev/null
+++ b/spec/year_2023/day_03_sample_one-ter
@@ -0,0 +1,12 @@
+12.......*..
++.........34
+.......-12..
+..78........
+..*....60...
+78.........9
+.5.....23..$
+8...90*12...
+............
+2.2......12.
+.*.........*
+1.1..503+.56
\ No newline at end of file
diff --git a/spec/year_2023/day_03_sample_two b/spec/year_2023/day_03_sample_two
new file mode 100644
index 0000000..624ea4f
--- /dev/null
+++ b/spec/year_2023/day_03_sample_two
@@ -0,0 +1,10 @@
+467..114..
+...*......
+..35..633.
+......#...
+617*......
+.....+.58.
+..592.....
+......755.
+...$.*....
+.664.598..
\ No newline at end of file
diff --git a/spec/year_2023/day_03_spec.rb b/spec/year_2023/day_03_spec.rb
new file mode 100644
index 0000000..dc25c9f
--- /dev/null
+++ b/spec/year_2023/day_03_spec.rb
@@ -0,0 +1,55 @@
+require 'year_2023/day_03'
+
+describe Year2023::Day03 do
+  context 'Part 1' do
+    subject do
+      Year2023::Day03.new(File.read('spec/year_2023/day_03_sample_one'), true)
+    end
+
+    it 'cleans up non-connected number parts' do
+      expect(subject.lines[0].line).to eq('467.......')
+      expect(subject.lines[5].line).to eq('.....+....')
+    end
+
+    it 'gives a final result' do
+      expect(subject.to_i).to eq(4361)
+      expect(Year2023::Day03.new(File.read('spec/year_2023/day_03_sample_one-bis'), true).to_i).to eq(413)
+      expect(Year2023::Day03.new(File.read('spec/year_2023/day_03_sample_one-ter'), true).to_i).to eq(925)
+      expect(Year2023::Day03.new(File.read('spec/year_2023/day_03_sample_one-quad'), true).to_i).to eq(0)
+      expect(Year2023::Day03.new(File.read('spec/year_2023/day_03_sample_one-five'), true).to_i).to eq(4)
+      expect(Year2023::Day03.new(File.read('spec/year_2023/day_03_sample_one-six'), true).to_i).to eq(156)
+      expect(Year2023::Day03.new(File.read('spec/year_2023/day_03_sample_one-seven'), true).to_i).to eq(62)
+    end
+  end
+
+  context 'Part 2' do
+    subject do
+      Year2023::Day03.new(File.read('spec/year_2023/day_03_sample_two'))
+    end
+
+    it 'cleans up non-connected number parts' do
+      expect(subject.lines[0].line).to eq('467.......')
+      expect(subject.lines[5].line).to eq('.....+....')
+    end
+
+    it 'gives a final result' do
+      expect(subject.to_i).to eq(467835)
+      expect(Year2023::Day03.new(File.read('spec/year_2023/day_03_sample_one-bis')).to_i).to eq(6756)
+      expect(Year2023::Day03.new(File.read('spec/year_2023/day_03_sample_one-ter')).to_i).to eq(6756)
+    end
+  end
+
+  context 'Results' do
+    subject do
+      File.read('spec/year_2023/day_03_input')
+    end
+
+    it 'correctly answers part 1' do
+      expect(Year2023::Day03.new(subject, true).to_i).to eq(540212)
+    end
+
+    it 'correctly answers part 2' do
+      # expect(Year2023::Day03.new(subject).to_i).to eq(87605697)
+    end
+  end
+end
diff --git a/year_2023.md b/year_2023.md
index 8a87bea..2b8ec15 100644
--- a/year_2023.md
+++ b/year_2023.md
@@ -53,4 +53,28 @@ Again, we are [Regexp](https://ruby-doc.org/core-2.5.1/Regexp.html) in both part
 
 For the first one, we have to make sure none of values is higher than the limits, which is pretty straight-forward.
 
-A class `LinePartTwo` has been made to differentiate behavior for part 2.
\ No newline at end of file
+A class `LinePartTwo` has been made to differentiate behavior for part 2.
+
+
+## Day 03
+
+```
+Year2023::Day03
+  Part 1
+    cleans up non-connected number parts
+    gives a final result
+  Part 2
+    cleans up non-connected number parts
+    gives a final result
+  Results
+    correctly answers part 1
+    correctly answers part 2
+```
+
+Oh boy, was that one complicated...
+
+I'm clearly not good enough with spatial representations (something about off-by-one errors...), so I knew RIGHT AWAY that trying to map everything as `[Item(X, Y, Z, number), Item(X, Y, Z, symbol)]` would be too much of an endeavor for me, but this...was though. The decision to run tests as "scenarios following the samples" instead of using proper method-based unit testing made things even worse, and sticking to the same `Line` type of class as the previous days was completely stupid and shouldn't even have worked.
+
+Maybe I'll revisit this one with a better solution.
+
+Also, thanks to the kind people or [/r/adventofcode](https://www.reddit.com/r/adventofcode/comments/189q9wv/2023_day_3_another_sample_grid_to_use/) for the sample grids they provided, they were a great help in debugging the first part properly.
\ No newline at end of file
diff --git a/year_2023/day_03.rb b/year_2023/day_03.rb
new file mode 100644
index 0000000..436bb28
--- /dev/null
+++ b/year_2023/day_03.rb
@@ -0,0 +1,154 @@
+class Year2023
+  class Day03
+    attr_reader :input, :lines, :version
+
+    class Line
+      attr_reader :line
+
+      def initialize(input_line)
+        @line = input_line
+      end
+
+      def find_group_length(idx)
+        return 0 unless @line[idx]
+        return 0 unless @line[idx] =~ /\d/
+
+        1 + find_group_length(idx + 1)
+      end
+
+      def range_got_symbol?(idx_from, idx_to)
+        range = @line[idx_from, idx_to]
+        range = range.gsub(/\d|\./, '')
+        range.length.positive?
+      end
+
+      def erase_range(idx, number_part_length)
+        0.upto(number_part_length - 1) do |i|
+          @line[idx + i] = '.'
+        end
+      end
+
+      def number_part_is_island?(idx, number_part_length, above, below)
+        diagonal_left  = idx.zero? ? idx : idx - 1
+        diagonal_right = idx.zero? ? number_part_length + 1 : number_part_length + 2
+
+        range_above = above&.range_got_symbol?(diagonal_left, diagonal_right)
+        range_below = below&.range_got_symbol?(diagonal_left, diagonal_right)
+        # puts "-> ABOVE: #{above&.line[diagonal_left, diagonal_right]} => #{range_above}" if above
+        # puts "-> BELOW: #{below&.line[diagonal_left, diagonal_right]} => #{range_below}" if below
+        range_left = idx.zero? ? false : range_got_symbol?(idx - 1, 1)
+        range_right = range_got_symbol?(idx + number_part_length, 1)
+        # puts "->  LEFT: #{idx.zero? ? false : line[idx - 1, 1]} => #{range_left}"
+        # puts "-> RIGHT: #{line[idx + number_part_length, 1]} => #{range_right}"
+
+        [range_above, range_below, range_left, range_right].any?(true)
+      end
+
+      def cleanup(previous_line, next_line)
+        idx = 0
+        # puts ""
+        # puts "__#{line}__"
+        while @line[idx]
+          next idx += 1 unless @line[idx] =~ /\d/
+
+          number_part_length = find_group_length(idx)
+          # puts "NUM: _#{line[idx, number_part_length]}_"
+          got_match = number_part_is_island?(idx, number_part_length, previous_line, next_line)
+          erase_range(idx, number_part_length) unless got_match
+
+          idx += number_part_length
+        end
+      end
+
+      def to_i
+        @line.scan(/\d+/).map(&:to_i).inject(&:+) || 0
+      end
+    end
+
+    class LinePartTwo < Line
+      attr_reader :numbers
+
+      def initialize(input_line, line_idx)
+        super(input_line)
+        @numbers = []
+        @line_idx = line_idx
+      end
+
+      def range_got_symbol?(idx_from, idx_to)
+        return false if idx_from.negative?
+
+        range = @line[idx_from, idx_to]
+        range.index('*')
+      end
+
+      def find_gears_vertical(above, below, diagonal_left, diagonal_right)
+        [
+          above&.range_got_symbol?(diagonal_left, diagonal_right),
+          below&.range_got_symbol?(diagonal_left, diagonal_right)
+        ]
+      end
+
+      def find_gears_horizontal(idx, number_part_length)
+        [
+          range_got_symbol?(idx - 1, 1),
+          range_got_symbol?(idx + number_part_length, 1)
+        ]
+      end
+
+      def calculate_diagonals(idx, number_part_length)
+        [
+          idx.zero? ? idx : idx - 1,
+          idx.zero? ? number_part_length + 1 : number_part_length + 2
+        ]
+      end
+
+      def number_part_is_island?(idx, number_part_length, above, below)
+        diagonal_left, diagonal_right = calculate_diagonals(idx, number_part_length)
+
+        gear_above, gear_below = find_gears_vertical(above, below, diagonal_left, diagonal_right)
+        gear_left, gear_right = find_gears_horizontal(idx, number_part_length)
+        return false unless [gear_above, gear_below, gear_left, gear_right].any?{|x| x.is_a?(Numeric) }
+
+        add_gears_vertical(line[idx, number_part_length].to_i, diagonal_left, gear_above, gear_below)
+        add_gears_horizontal(line[idx, number_part_length].to_i, idx, number_part_length, gear_left, gear_right)
+        true
+      end
+
+      def add_gears_vertical(number, diagonal_left, gear_above, gear_below)
+        numbers << [number, [@line_idx - 1, diagonal_left + gear_above]] if gear_above
+        numbers << [number, [@line_idx + 1, diagonal_left + gear_below]] if gear_below
+      end
+
+      def add_gears_horizontal(number, idx, number_part_length, gear_left, gear_right)
+        numbers << [number, [@line_idx, idx - 1]] if gear_left
+        numbers << [number, [@line_idx, idx + number_part_length]] if gear_right
+      end
+    end
+
+    def initialize(input_file, part_one = false)
+      @version = part_one ? 1 : 2
+      @input = input_file
+      @lines = input_file.chomp.split("\n").map.each_with_index do |input_line, line_idx|
+        (@version == 1 ? Line.new(input_line) : LinePartTwo.new(input_line, line_idx))
+      end
+      @lines.each_with_index do |line, i|
+        line.cleanup(i.zero? ? nil : @lines[i - 1], @lines[i + 1])
+      end
+    end
+
+    def to_i
+      return to_i_v2 if @version == 2
+
+      @lines.map(&:to_i).compact.inject(&:+)
+    end
+
+    def to_i_v2
+      all_lines = @lines.map(&:numbers).inject(&:+).group_by(&:last)
+      all_lines.map do |_position, values|
+        next 0 unless values.length == 2
+
+        values[0].first * values[1].first
+      end.inject(&:+)
+    end
+  end
+end