#include<stdio.h>
char tran(char c,int n){
    char r;
    if(c+n<=122)r=c+n;
    if(c+n>122)r=tran(c,n-26);
    return r;
}
int main(){
    int n;
    char c,r;
    scanf("%d",&n);
    getchar();
    while(1){
        c=getchar();
        if(c<97||c>122)return 0;
        r=tran(c,n);
        printf("%c",r);
    }
}