#!/bin/python

import sys
import string

n = int(raw_input().strip())
s = raw_input().strip()
k = int(raw_input().strip())

Ans=[]
for i in xrange(n):
	if s[i] in string.letters:
		#something like --> (97+((ord(s[i])+k)%12))
		Ans.append(chr(ord(s[i]) + k))
	else:
		Ans.append(s[i])

print "".join(Ans)