package HackerRank; import java.util.Scanner; class UsernameValidator { /* * Write regular expression here. */ public static final String regularExpression = "^[a-zA-Z]\\w{7,29}$"; } public class TwentyEight { private static final Scanner scan = new Scanner(System.in); public static void main(String[] args) { int n = Integer.parseInt(scan.nextLine()); while (n-- != 0) { String userName = scan.nextLine(); if (userName.matches(UsernameValidator.regularExpression)) { System.out.println("Valid"); } else { System.out.println("Invalid"); } } } }