#!/usr/bin/env python
# -*- coding: utf-8 -*-
import os
class caesar_cipher:
 
 
	def cipher(self):
		self.dic_let = {'a':'d','b':'e','c':'f','d':'g','e':'h','f':'i','g':'j','h':'k','i':'l',
		'j':'m','k':'n','l':'o','m':'p','n':'q','o':'r','p':'s','q':'t','r':'u','s':'v','t':'w','u':'x','v':'y',
		'w':'z','x':'a','y':'b','z':'c'}
		print "Inserte la cadena a cifrar"
		self.cadena = raw_input("Cadena>")
		for self.letra in self.cadena:
			if self.letra == self.letra.upper():
				print self.dic_let[self.letra.lower()],
			else:
				print self.dic_let[self.letra],
 
if __name__ == '__main__':
	print "1-Cifrar o 2-descifrar?"
	eleccion = input(">")
	if eleccion == 1:
		os.system("clear")
		t = caesar_cipher()
		t.cipher()
 
	elif eleccion ==2:
		os.system("clear")
		t = caesar_cipher()
		t.uncipher()