int addUser(Account &a)
{
    vector<Account>::iterator it;
    if (it == info.begin() && it == info.end())
    {
        if (a._password.size() < 8)
        {
            cout << "Registration failed" << endl;
            return 0;
        }
        else { info.push_back(a); }
    }
    else
    {
        for (it = info.begin(); it != info.end(); ++it)
        {
            if (a._login == it->_login)
            {
                cout << "Registration failed" << endl;
                return 0;
            }
            if (a._password.size() < 8)
            {
                cout << "Registration failed" << endl;
                return 0;
            }
            else { info.push_back(a); }
            cout << "Hello" << endl;
        }
    }
    cout << "Successfully added!" << endl;
}

int authorize(Account &a)
{
    vector<Account>::iterator it;
    bool accept;
    accept = false;
    for (it = info.begin(); it != info.end(); ++it)
    {
        cout << "Hello" << endl;
        if (a._login == it->_login)
            if (a._password == it->_password)
            {
                accept = true;
                return 0;
            }
            else { accept = false; }
    }
    if (accept)
    {
        cout << "Online" << endl;
        return 0;
    }
    else { cout << "Authorization failed" << endl; }
    return 1;
}