import java.io.BufferedReader;
import java.io.InputStreamReader;

public class Main {
	public static void main(String[] args) throws Exception {

		BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
		String str = reader.readLine();
		int N = Integer.parseInt(str);
		char[] ary = reader.readLine().toCharArray();
		
		char[] alphabet = new char[26];
		char c = 'A';
		for (int i = 0; i < 26; i++) {
			alphabet[i] = c++;
		}
		
		for (int i = 0; i < ary.length; i++) {
			int a = (int)ary[i] - (int)'A';
			a += N;
			a %= 26;
			System.out.print(alphabet[a]);
		}
		System.out.println();
	}
}
/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