input = File.read("day4.txt").chomp.split("-").map(&.to_i32)
total = 0
(input[1] - input[0]).times do |i|
  invalid = false
  i = (input[0] + i).to_s
  i.chars.each_cons_pair do |c1,c2|
    invalid = c2 < c1
    break if invalid
  end
  next if invalid

  # next unless i =~ /.*(.)\1.*/
  past_char = nil
  past_count = 0
  pasts = [] of Int32
  i.each_char do |c|
    if c == past_char
      past_count += 1
    else
      pasts << past_count
      past_count = 0
    end
    past_char = c
  end
  pasts << past_count

  total += 1 if pasts.any? &.==(1)
end
puts total