function rot (n, c) {
  const alpha = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'
  return alpha.charAt((alpha.indexOf(c) + n) % 26)
}

function main (input) {
  const line = input.split('\n')
  const n = parseInt(line[0], 10)
  const s = line[1]
  const ss = s.split('')

  console.log(ss.map((x) => rot(n, x)).join(''))
}

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