diff --git a/06/input b/06/input
new file mode 100644
index 0000000..df10465
--- /dev/null
+++ b/06/input
@@ -0,0 +1,300 @@
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diff --git a/06/script.rb b/06/script.rb
new file mode 100755
index 0000000..4cf7b85
--- /dev/null
+++ b/06/script.rb
@@ -0,0 +1,101 @@
+#!/usr/bin/env ruby
+
+require_relative '../common'
+
+class LightGrid
+  def initialize(brightness = false)
+    @brightness = brightness
+    @grid = Array.new(1000) { Array.new(1000, 0) }
+  end
+
+  def parse(instructions)
+    instructions.each do |string|
+      instruction, from_x, from_y, to_x, to_y = string.match(/\A(.*) ([0-9]+),([0-9]+) through ([0-9]+),([0-9]+)\z/).captures
+      klass = instruction_klass(instruction)
+
+      (from_x.to_i..to_x.to_i).each do |i|
+        (from_y.to_i..to_y.to_i).each do |j|
+          @grid[i][j] = klass.process(@grid[i][j])
+        end
+      end
+    end
+
+    @grid.flatten.sum
+  end
+
+  private
+
+  def instruction_klass(instruction)
+    if @brightness
+      case instruction
+      when "turn on"
+        Brightness::TurnOn
+      when "turn off"
+        Brightness::TurnOff
+      else
+        Brightness::Toggle
+      end
+    else
+      case instruction
+      when "turn on"
+        Simple::TurnOn
+      when "turn off"
+        Simple::TurnOff
+      else
+        Simple::Toggle
+      end
+    end
+  end
+
+  class Simple
+    class TurnOn
+      def self.process(value)
+        1
+      end
+    end
+
+    class TurnOff
+      def self.process(value)
+        0
+      end
+    end
+
+    class Toggle
+      def self.process(value)
+        value == 1 ? 0 : 1
+      end
+    end
+  end
+
+  class Brightness
+    class TurnOn
+      def self.process(value)
+        value + 1
+      end
+    end
+
+    class TurnOff
+      def self.process(value)
+        value > 0 ? value - 1 : 0
+      end
+    end
+
+    class Toggle
+      def self.process(value)
+        value + 2
+      end
+    end
+  end
+end
+
+class Day6 < Day
+  def part1
+    LightGrid.new.parse input
+  end
+
+  def part2
+    LightGrid.new(true).parse input
+  end
+end
+
+Day6.run
diff --git a/common.rb b/common.rb
index 55a9f65..d12c5bc 100644
--- a/common.rb
+++ b/common.rb
@@ -9,3 +9,36 @@ class Input
     File.readlines(@filename).reject { |line| line.start_with?('#') }
   end
 end
+
+class Day
+  def self.run
+    new.run
+  end
+
+  def part1
+  end
+
+  def part2
+  end
+
+  def run
+    puts "=== Part 1 ==="
+    puts part1
+    puts "=== Part 2 ==="
+    puts part2
+  end
+
+  private
+
+  def filename
+    "#{File.dirname($PROGRAM_NAME)}/input"
+  end
+
+  def input
+    @input ||= if File.exist?(filename)
+                 File.readlines(filename).reject { |line| line.start_with?('#') }.map(&:chomp)
+               else
+                 INPUT
+               end
+  end
+end