SantasSecretHelper

import java.util.Scanner;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

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

        Pattern pattern = Pattern.compile("\\@([A-Za-z]+)[^\\@\\-\\!\\:\\>]*\\!([A-Z])\\!");

        int n = Integer.parseInt(sc.nextLine());
        String input = sc.nextLine();

        while (!input.equals("end")){
            String decrypt = "";

            for (int i = 0; i < input.length(); i++){
                int ascii = (int)input.charAt(i) - n;
                decrypt += (char)ascii;
            }

            Matcher matcher = pattern.matcher(decrypt);

            while (matcher.find()){
                String behevier = matcher.group(2);

                if (behevier.equals("G")){
                    String name = matcher.group(1);
                    System.out.println(name);
                }
            }

            input = sc.nextLine();
        }
    }
}