object Main {
  def main(args:Array[String]) {
    val N = readLine().toInt    
    val S = readLine()
    var ans = List[Char]()
    for(i <- 0 until S.length) {
      ans = (((S(i) - 'A' + N) % 26) + 65).toChar :: ans
    }
    ans = ans.reverse
    ans.map{a => print(a)}
    println()
  }
}
