E01ValidUsernames

import java.util.Scanner;

public class E01ValidUsernames {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        String[] array = scanner.nextLine().trim().split(", ");


        for (String username : array) {
            boolean isValid = true;
            if (username.length() < 3 || 16 < username.length()) {
                isValid = false;
            }
            for (int j = 0; j < username.length(); j++) {
                char symbol = username.charAt(j);
                if (!Character.isLetterOrDigit(symbol) && symbol != '-' && symbol != '_') {
                    isValid = false;
                }
            }
            if (isValid) {
                System.out.println(username);
            }
        }
    }
}