#VET - Vigenere Encipherment Tool

import os, sys

def getText(string):

	text = raw_input(string)

	while len(text) == 0:
		text = raw_input(string)
	return text

def cipher(pchar, kchar):
	pascii = ord(pchar)
	kascii = ord(kchar)

	if kchar.isalpha():
		if kascii > 96:
			kascii = kascii - 97
		else:
			kascii = kascii - 65
	else:
		print 'invalid key sequence'
		raise SystemExit

	if pchar.isalpha():
		if pascii > 96:
			pascii = pascii + kascii
			if pascii > 122:
				pascii = pascii - 26
				return chr(pascii)
			else:
				return chr(pascii)
		else:
			pascii = pascii + kascii
			if pascii > 90:
				pascii = pascii - 26
				return chr(pascii)
			else: 
				return chr(pascii)
	else:
		return pchar

def cipherLoop(plaintext, key):

	keycounter = 0
	charcounter = 0
	keytext = key.replace(' ','')
	ciphertext = ''

	while charcounter < len(plaintext):
		keychar = keytext[keycounter]
		plainchar = plaintext[charcounter]
		charcounter = charcounter + 1
		if plainchar != ' ':
			ciphertext = ciphertext + cipher(plainchar, keychar)
			keycounter = keycounter + 1
			if keycounter == len(keytext):
				keycounter = 0
		else:
			ciphertext = ciphertext + ' '
	return ciphertext


print cipherLoop(getText('Please enter plaintext>'), getText('Please enter key>'))