'use strict';
function main(input) {
  const arr = input.trim().split('\n');
  const a = Number(arr[0]);
  const str = arr[1];
  const alp = 'ABCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHIJKLMNOPQRSTUVWXYZ';
  let ans = '';

  for (let i = 0; i < str.length; i ++) {
    ans[i] += alp[(alp.indexOf(str[i]) + a) % 26]
  }
  
  console.log(ans);
}

main(require("fs").readFileSync("/dev/stdin", "utf8"));