Recap - Validation Function

import java.util.Scanner;

public class Main {
    public static boolean is_valid(String username, String password) {
        // 아래에 코드를 작성하세요
        
    }
    
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        String user = scanner.nextLine();
        String pass = scanner.nextLine();
        boolean res = is_valid(user, pass);
        System.out.println(res);
    }
}