while s = gets do
  26.times do
    break if s.include?("the") || s.include?("this") || s.include?("that")
    s.length.times do |i|
      s[i] = (s[i].ord + 1).chr if 'a' <= s[i] && s[i] <= 'z'
      s[i] = 'a' if s[i].ord == 'z'.ord + 1
    end
  end
  puts s
end