diff --git a/day_12/first.rb b/day_12/first.rb
new file mode 100644
index 0000000..c2ea3b6
--- /dev/null
+++ b/day_12/first.rb
@@ -0,0 +1,34 @@
+# frozen_string_literal: true
+
+input = File.readlines('./input').map do |line|
+  [line[0], Integer(line[1..-1])]
+end
+
+DIRS = { 0 => 'N', 1 => 'E', 2 => 'S', 3 => 'W' }.freeze
+
+$position = [0, 0, 90]
+
+def move(action, value)
+  case action
+  when 'N'
+    $position[1] += value
+  when 'S'
+    $position[1] -= value
+  when 'E'
+    $position[0] += value
+  when 'W'
+    $position[0] -= value
+  when 'L'
+    $position[2] -= value
+  when 'R'
+    $position[2] += value
+  when 'F'
+    move(DIRS[$position[2] / 90 % 4], value)
+  end
+end
+
+input.each do |instr|
+  move(*instr)
+end
+
+puts $position.values_at(0, 1).map(&:abs).sum
diff --git a/day_12/input b/day_12/input
new file mode 100644
index 0000000..7b923fc
--- /dev/null
+++ b/day_12/input
@@ -0,0 +1,774 @@
+E2
+L180
+S4
+R90
+S1
+F49
+N2
+F18
+N2
+L180
+S5
+L90
+E3
+N2
+F11
+L180
+N5
+W3
+L180
+W2
+N5
+F80
+R90
+F89
+N1
+L180
+N2
+R180
+E4
+R90
+S1
+L90
+N5
+R180
+N2
+F17
+L90
+E2
+F58
+W5
+L90
+W3
+N3
+F78
+L90
+N4
+L90
+F15
+W1
+R90
+S1
+W4
+R90
+F41
+W4
+S4
+F37
+E5
+S1
+E3
+F19
+R90
+S1
+W4
+S2
+E2
+L180
+F51
+W5
+R90
+F76
+E2
+F40
+N4
+R180
+E5
+N3
+F72
+S4
+R90
+F99
+E3
+F76
+W5
+R90
+E2
+S5
+R180
+F76
+N4
+L180
+F10
+F83
+S1
+F46
+L90
+S5
+E1
+S1
+F14
+N4
+E1
+R180
+E1
+R180
+S3
+F52
+L90
+S4
+L90
+W3
+F18
+S2
+F81
+L180
+F76
+L180
+W1
+S2
+F73
+N2
+F77
+W1
+F28
+L180
+N2
+F76
+L180
+W5
+F61
+N4
+E2
+R180
+S2
+L90
+F14
+R180
+N5
+E4
+F11
+E1
+L90
+N3
+E3
+F58
+W3
+F72
+W1
+N2
+W5
+F44
+L90
+W4
+F37
+L90
+F4
+W5
+N3
+F57
+N4
+L90
+S2
+F43
+S4
+W3
+S5
+F84
+S2
+L90
+N1
+R180
+W3
+L180
+N2
+W3
+R90
+N2
+R90
+F66
+L90
+F73
+E4
+S2
+L270
+W2
+E2
+S4
+E1
+R90
+W1
+F49
+L270
+F70
+S3
+W1
+N2
+E1
+F65
+W3
+R90
+F27
+E5
+F80
+S4
+W5
+F68
+E5
+R90
+F94
+W2
+L90
+F37
+L180
+E1
+F38
+N2
+F15
+N4
+E3
+L90
+E1
+R90
+S1
+E5
+N4
+N2
+E4
+L270
+N4
+R90
+E1
+S4
+E4
+F71
+E2
+R180
+N5
+E3
+F17
+L90
+N2
+W1
+L90
+F62
+W1
+F85
+W1
+L180
+F33
+S4
+W1
+N5
+F81
+W2
+R90
+S2
+F49
+L180
+S5
+F4
+W4
+N3
+W1
+F17
+R90
+W4
+N4
+E4
+N3
+L90
+S2
+R90
+S3
+L90
+E4
+R90
+S5
+F88
+S1
+L180
+N5
+E5
+F55
+R90
+F81
+E5
+L180
+R90
+F55
+R90
+W5
+F13
+R90
+N5
+F58
+L180
+S5
+F27
+E4
+S3
+F42
+R90
+F39
+W3
+S3
+F31
+S4
+L90
+W1
+S3
+W3
+N4
+W2
+S3
+L90
+F61
+E1
+F23
+S2
+F31
+S3
+L180
+W1
+N1
+L90
+N3
+F81
+E2
+N1
+R90
+F64
+S4
+F88
+E1
+N5
+W1
+S3
+F10
+N5
+L90
+F58
+S1
+R90
+E3
+L90
+N4
+F94
+S1
+W1
+S4
+L90
+F51
+L180
+N4
+R90
+L90
+N4
+F66
+W2
+S3
+S3
+W4
+F68
+L90
+F42
+E1
+F43
+R90
+N3
+F20
+E1
+N3
+E4
+N3
+F4
+S4
+R180
+W1
+R270
+N3
+F86
+L90
+E5
+F84
+N3
+W3
+F16
+L90
+N2
+E3
+L90
+S5
+E5
+F53
+L270
+N2
+F91
+R90
+E5
+N4
+F57
+E5
+S5
+F61
+S4
+F89
+E3
+N3
+N5
+F3
+S5
+F59
+E5
+F66
+R180
+S1
+W1
+N2
+R180
+S4
+E2
+L90
+N1
+W2
+F13
+L90
+E5
+F6
+W3
+F78
+E1
+F7
+W1
+N4
+W5
+F58
+R90
+E4
+N3
+E5
+N3
+W1
+S3
+R90
+F16
+L90
+F93
+R270
+N5
+F2
+W1
+S3
+F54
+R270
+F18
+R180
+F95
+L90
+W1
+E4
+N2
+W1
+L90
+S2
+L90
+W2
+S4
+F92
+W2
+S3
+R180
+N5
+E3
+N5
+E5
+F22
+F88
+S3
+E2
+R90
+S5
+W1
+L90
+E4
+F77
+N1
+W3
+F14
+E3
+R90
+W1
+F21
+N1
+F58
+W4
+N2
+R90
+N2
+W4
+F68
+W5
+N3
+L90
+F22
+R90
+F90
+F84
+S5
+F30
+N1
+W4
+R90
+F17
+R90
+W4
+S5
+E2
+N1
+F92
+N2
+R180
+N5
+E2
+R90
+F38
+R90
+F15
+E5
+N4
+N4
+E4
+S4
+F92
+R90
+F22
+S3
+W4
+N3
+E1
+R180
+F96
+L90
+E1
+N1
+F9
+W2
+N4
+F17
+N2
+R90
+F76
+S2
+F5
+S5
+F34
+R90
+F7
+N4
+F83
+N5
+L90
+W1
+S3
+R90
+S3
+W2
+S3
+F51
+N5
+W4
+F8
+E3
+F10
+N5
+F39
+S3
+E2
+L90
+E5
+L90
+N5
+E2
+N3
+F42
+S3
+F38
+N5
+F19
+F97
+W2
+R180
+S4
+E4
+S2
+W3
+F39
+W4
+F70
+S1
+W1
+R90
+F41
+L90
+E1
+N1
+E3
+W5
+F13
+E4
+F2
+R180
+F27
+E4
+N2
+L270
+E1
+N3
+W4
+F81
+W3
+R90
+E1
+F57
+S5
+R90
+F13
+L180
+N5
+F98
+F32
+N3
+R90
+N3
+W3
+S3
+W3
+N4
+F73
+L180
+N1
+E4
+F7
+E4
+R90
+N4
+R90
+S2
+E5
+F32
+S2
+N5
+W3
+R90
+W5
+S2
+L90
+F4
+R270
+N5
+E3
+L90
+S5
+F24
+N4
+R90
+F27
+L90
+F16
+R90
+N2
+R90
+N3
+L90
+S3
+L90
+F85
+S3
+F47
+N1
+E1
+N3
+R270
+S2
+L90
+F50
+L90
+S2
+F23
+N4
+L180
+E3
+F91
+R90
+E1
+W4
+F81
+W5
+R90
+F46
+E1
+W1
+F91
+N5
+W5
+N3
+W1
+L90
+F60
+S2
+L90
+E1
+F82
+S3
+W5
+N5
+F90
+E3
+S1
+F61
+E4
+F98
+R180
+F8
+R270
+F73
+W4
+L90
+W5
+L90
+F86
+W5
+L180
+F61
+N5
+F88
+E2
+L270
+F90
+N5
+F21
+R270
+F40
+L90
+W1
+N2
+L90
+E2
+S5
+E2
+S1
+E5
+N3
+F51
+S1
+F58
+W3
+L180
+F13
+R90
+N1
+F79
+W2
+F61
+R90
+F22
+E2
+N5
+F1
+S4
+F99
+S1
+S3
+E2
+F97
diff --git a/day_12/second.rb b/day_12/second.rb
new file mode 100644
index 0000000..4777106
--- /dev/null
+++ b/day_12/second.rb
@@ -0,0 +1,45 @@
+# frozen_string_literal: true
+
+input = File.readlines('./input').map do |line|
+  [line[0], Integer(line[1..-1])]
+end
+
+$position = [0, 0]
+$waypoint = [10, 1]
+
+def rad(deg)
+  deg * Math::PI / 180
+end
+
+def rotate(deg)
+  x,y = $waypoint
+  rad = rad(deg)
+  $waypoint[0] = (x*Math.cos(rad) - y*Math.sin(rad)).round
+  $waypoint[1] = (x*Math.sin(rad) + y*Math.cos(rad)).round
+end
+
+def move(action, value)
+  case action
+  when 'N'
+    $waypoint[1] += value
+  when 'S'
+    $waypoint[1] -= value
+  when 'E'
+    $waypoint[0] += value
+  when 'W'
+    $waypoint[0] -= value
+  when 'L'
+    rotate(value)
+  when 'R'
+    rotate(-value)
+  when 'F'
+    $position[0] += $waypoint[0] * value
+    $position[1] += $waypoint[1] * value
+  end
+end
+
+input.each do |instr|
+  move(*instr)
+end
+
+puts $position.values_at(0, 1).map(&:abs).sum
diff --git a/day_12/test b/day_12/test
new file mode 100644
index 0000000..d382291
--- /dev/null
+++ b/day_12/test
@@ -0,0 +1,5 @@
+F10
+N3
+F7
+R90
+F11