#include <cstdio>
    #include <string.h>
    #include <iostream>
    #include <algorithm>
    #include <math.h>
    #include <vector>
    using namespace std;

    int main()
    {
        int n;
        cin>>n;
        getchar();
        char s;
        while(1){
            s=getchar();
            if(s == '\n'){
                break;
            }
            s=(s-'a'+n)%26+'a';
            putchar(s);
        }	

        return 0;
    }