import java.util.Scanner;

fun main (args : Array<String>) {
  val input = Scanner(System.`in`)
  
  while (input.hasNext()) {
    val N = input.nextInt()
    val S = input.next().toCharArray()
    
    for (i in 0..(S.size - 1)) {
      S[i] = 'A'.plus((S[i].minus('A') + N) % 26);
    }
    
    println(S)
  }
}