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You are updating the username policy on your company’s internal networking platform. According to the policy, a username is considered valid if all the following constraints are satisfied:

Sample Input

8
Julia
Samantha
Samantha_21
1Samantha
Samantha?10_2A
JuliaZ007
Julia@007
_Julia007

Sample Output

Invalid
Valid
Valid
Invalid
Invalid
Valid
Invalid
Invalid

SOLUTION:

import java.util.Scanner;
class UsernameValidator {
    /*
     * Write regular expression here.
     */
    public static final String regularExpression = "[A-Za-z][A-Za-z0-9_]{7,29}";
}


public class Solution {
    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");
            }
        }
    }
}

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