01. Valid Usernames

#include <iostream>
#include <string>

using namespace std;

int main() {
    string passwords, pass;
    getline(cin, passwords);

    while (passwords.length() != 0) {
        pass = passwords.substr(0, passwords.find(", "));
        passwords.erase(0, pass.length() + 2);
        bool isValid = true;
        if (pass.length() > 3 && pass.length() <= 16) {
            for (size_t i = 0; i < pass.length(); i++) {
                if (!isalpha(pass[i]) && !isdigit(pass[i]) && pass[i] != '-' && pass[i] != '_') {
                    isValid = false;
                    continue;
                }
            }
        }
        else {
            continue;
        }

        if (isValid) {
            cout << pass << endl;
        }
    }

    return 0;
}