import java.util.Scanner;

public class Solution {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        String s = sc.next();
        int k = sc.nextInt() % 26;
        String alphabets = "abcdefghijklmnopqrstuvwxyz";
        char[] lowercase = alphabets.toCharArray();
        char[] uppercase = alphabets.toUpperCase().toCharArray();

        StringBuilder result = new StringBuilder();

        for (char ch : s.toCharArray()) {
            if (Character.isUpperCase(ch)) {
                int x = 26 - (ch - 65);
                result.append((char) (x <= k ? uppercase[k - x] : ch + k));
            }

            else if (Character.isLowerCase(ch)) {
                int x = 26 - (ch - 97);
                result.append((char) (x <= k ? lowercase[k - x] : ch + k));
            }

            else result.append(ch);
        }

        System.out.println(result);
    }
}