NC14112：Check In不能通过所有用例

import java.util.Scanner;
import java.util.regex.*;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int group = sc.nextInt();
        sc.nextLine();
        while(group>0)
        {
            int x = sc.nextInt();
            sc.nextLine();
            int num = 0;
            while(x >0)
            {
                String str = sc.nextLine();

                String regex = "bnu16-\\d";
                Pattern pattern = Pattern.compile(regex);
                Matcher matcher = pattern.matcher(str);
                if (matcher.matches()) {
                    num += 1;
                }
                x--;
            }
            System.out.println(num);
            group--;
        }
    }
}

https://ac.nowcoder.com/acm/problem/14112

自己输入了很多组用例答案都是正确的，为什么通过率为0？求大佬教教