function Main(input) {
  input = input.split("\n");
  var N = input[0];
  N -=1;
  N +=1;
  var S = input[1];
  for(var i = 0;i<S.length;i++){
    process.stdout.write(String.fromCodePoint(65+((S.charCodeAt(i)-65)+N)%26));
 }
}
Main(require("fs").readFileSync("/dev/stdin", "utf8"));