#include <iostream>
#define int long long
using namespace std;
string s;
signed main() {
    int n;
    while(cin>>n){
        cin.ignore();
        getline(cin,s);
        for(int i = 0;i<s.size();i++){
            s[i] += n;
            if(s[i]>'z'){
                s[i]-=26;
            }
        }
        cout<<s<<endl;
    }

    return 0;
}