module CaesarCipher
	def self.encrypt(s, shift)
		s.bytes.map { |b| ((b + shift) % 0xFF).chr }.join
	end

	def self.decrypt(s, shift)
		s.bytes.map { |b| ((b - shift + 0xFF) % 0xFF).chr }.join
	end
end

KEY = 33

input = gets
encrypted = CaesarCipher.encrypt input, KEY
decrypted = CaesarCipher.decrypt encrypted, KEY
puts decrypted