#define _CRT_SECURE_NO_WARNINGS 1
#include<iostream>
#include<string.h>
using namespace std;
int main()
{
	char y[27] = "abcdefghijklmnopqrstuvwxyz";
	int n;
	cin >> n;
	getchar();//吞掉回车
	char a[55];
	cin.getline(a, 55);
	int len = strlen(a);
	for (int i = 0;i < len;i++) {
		for (int k = 0;k < 26;k++) {
			if (a[i] == y[k]) {
				a[i] = y[(k+=n) % 26];
			}
		}
	}
	cout << a;
	return 0;
}