#include<bits/stdc++.h>
using namespace std;
int main(){
    int n,a[50];
    string s;
    cin>>n;
    cin>>s;
    for(int i=0;i<s.length();i++){
        a[i]=s[i];
        a[i]+=n;
        if(a[i]>127){a[i]=a[i]-26;}
        s[i]=a[i];
        cout<<s[i];
    }
    return 0;
}