"use strict"
 const Main = (input) =>{
   let xs = input.trim().split('\n');
   let str =xs[1].split('');
   let ans =[];
   let N = Number(xs[0])
   
   for(let i=0;i<str.length; i++){
     Number(ans.push(str[i].charCodeAt()+N));
   }
   let ans1 =[];
   for(let i=0;i<str.length; i++){
     if(ans[i]>90){
       ans1.push(String.fromCharCode(ans[i]-26));
     }else{
       ans1.push(String.fromCharCode(ans[i]));
     }
   }
    let ans3 = '';
    for(let i=0;i<str.length; i++){
       ans3+=ans1[i];
   }
     console.log(ans3);
 }
Main(require("fs").readFileSync("/dev/stdin", "utf8"));