#define _CRT_SECURE_NO_WARNINGS
#include <iostream>
#include <cstdio>
using namespace std;
int main()
{
    int n;
    char a[110];
    cin >> n >> a;
    int k = n % 26;
    for (int i = 0; a[i] != '\0'; i++)
    {
        a[i] = a[i] + k;
        if (a[i] > 122)
        {
            a[i] = a[i] - 122 + 96;
        }
        printf("%c", a[i]);
    }
    
    return 0;
}