'use strict'
function Main(input) {
  const Num = input.split("\n").map(Number)[0]
  let S = input.split("\n")[1];
  // console.log({ Num, S });

  let SCode = [];
  let NCode = [];

  for (let i = 0; i < S.length; i++) {
    SCode.push(S.charCodeAt(i));
  }
  // console.log({ SCode });

  NCode = SCode.map(function (value) {
    let nValue = value + Num;
    // console.log({ nValue, value, Num });
    if (nValue > 90) {
      nValue = nValue - 26;
    }
    return nValue;
  })

  // console.log({ NCode });
  let Ans = NCode.map(function (value) {
    let nValue = String.fromCharCode(value)
    return nValue;
  })
  console.log(Ans.join(''));
}
Main(require("fs").readFileSync("/dev/stdin", "utf8"));