function myin(){return require("fs").readFileSync("/dev/stdin", "utf8").trim();}
function myout(t){console.log(t);}//standard output
//[no]param
//0:何もしない  1:数値へ変換  2:半角SPで分割  3:改行で分割  4:半角SPで分割し、数値配列へ
//5:改行で分割し、数値配列へ  6:1文字に分割  7:1文字に分割し、数値配列へ
function myconv(i,no){switch(no){case 0:return i;case 1:return parseInt(i);case 2:return i.split(" ");case 3:return i.split("\n");case 4:return i.split(" ").map((a)=>Number(a));case 5:return i.split("\n").map((a)=>Number(a));case 6:return i.split("");case 7:return i.split("").map((a)=>Number(a));}}

function Main(input) {
  input = myconv(input,3);
  var N = myconv(input[0],1);
  if(N == 0 || N == 26){
     myout(input[1]);
  }else{
    var inList = myconv(input[1],6);
    var list = "abcdefghijklmnopqrstuvwxyz".toUpperCase().split("");
    var output = "";
    for(var i = 0; i < inList.length; i++){
      var tmp = inList[i];
      var no = list.indexOf(tmp);
      no += N;
      //myout("in:" + tmp + ",no:" + no);
      if(no > 25){
         no -= 26;
      }
      
      output += list[no];
      //myout("no:" + no + ",add:" + list[no]);
    }
    myout(output);
  }
}

Main(myin());
