require 'set'

@input = File.read("6.input").split("\n")

def part(window_size)
  @input[0].chars.each_with_index do |c, i|
    chunk = @input[0].chars[(i..i+(window_size-1))]
    if Set.new(chunk).length == window_size then
      puts i + window_size
      break
    end
  end
end

part(4)
part(14)