function Main(input) {
  var N = parseInt(input[0], 10);
  var S = input[1];

  var len = S.length;
  var result = "";
  for (var i = 0; i < len; i++) {
    var num = S.charCodeAt(i);
    // console.log("%s", num);
    var new_num = num + N;
    if (new_num > 90) {
      new_num = new_num - 90 + 64;
    }
    result += String.fromCharCode(new_num);
  }
  console.log("%s", result);
}

Main(
  require("fs")
    .readFileSync("/dev/stdin", "utf8")
    .split("\n")
);
