import java.util.*;

public class Uebung5AufgabeVictorOdukoya {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);

    String Alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
    int k = sc.nextInt();
    String s1 = sc.next();
    char b =  s1.charAt(0);

    k = (k + Alphabet.indexOf(b)) % 26;

    System.out.println(Alphabet.charAt(k));
  }
}