import java.util.*;
class Main{
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    int N = sc.nextInt();
    String S = sc.next();
    String Alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
    String[] AlTable = Alphabet.split("",0);
    String ans = "";
    for(int i=0;i<S.length();i++){
      String tmp = S.substring(i,i+1);
      for(int j=0;j<26;j++){
        if(tmp.equals(AlTable[j])){
          int j2 = j + N;
          if(j2>=26){
            j2 = j2-26;
          }
          ans = ans + AlTable[j2];
        }
      }
    }
    System.out.println(ans);
  }
}
/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz