#include<iostream>
#include<cstring>
#include<string>
#include<cstdio>
#include<cmath>
#include<algorithm>
using namespace std;
string v="abcdefghijklmnopqrstuvwxyz";
int main(){
	int a;
	string mima;
	cin >> a >> mima;
	int tmp;
	for(int i=0;i<mima.length();i++){
		tmp = mima[i]-'a';
		tmp+=a;
		mima[i] = v[tmp%26]; 
	}
	cout << mima;
	return 0;
}

#include <bits/stdc++.h>
using namespace std;
string v="abcdefghijklmnopqrstuvwxyz";
int main(){
	int a;
	string mima;
	cin >> a >> mima;
	int tmp;
	for(int i=0;i<mima.length();i++){
		tmp = mima[i]-'a';
		tmp+=a;
		mima[i] = v[tmp%26]; 
	}
	cout << mima;
	return 0;
}