import java.util.*;

public class Main{
	public static void main(String args[]){
		Scanner sc = new Scanner(System.in);
		int N = sc.nextInt();
		String S = sc.next();
		char[] moji = S.toCharArray();
		for(int i = 0; i < moji.length; i ++){
			System.out.print((char)(mojiAdd(moji[i], N)));
		}
		System.out.println();
	}

	public static int mojiAdd(char moji, int N){
		if((int)(moji) + N > 90){
			return (int)(moji) + N - 26;
		}else{
			return (int)(moji) + N;
		}
	}
}

/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