function Main (input){
  input = input.split("\n");
  tmp = input[0].split(" ");  
  var N = parseInt(tmp[0],10);
  var S = input[1];
  var answer = ""
  var alph = ["A","B","C","D","E","F","G","H","I","J","K","L","M","N","O","P","Q","R","S","T","U","V","W","X","Y","Z"]
  for(var i=0; i<S.length; i++){
    x = S.charAt(i);
    var zurasi = (alph.indexOf(x) + N)%26;
    answer +=alph[zurasi];
  }
  console.log(answer);
}
Main(require("fs").readFileSync("/dev/stdin", "utf8"));