bool correct_parentheses(std::string seq)
{
    std::stack<char> x;
    std::map<char, char> p;
    p['('] = ')';
    p['['] = ']';
    for (auto t : seq)
    {
        if (t == '(' || t == '[')
            x.push(t);
        if (t == ')' || t == ']')
        {
            if (p[x.top()] == t)
                x.pop();
            else
                return false;
        }
    }
    return x.empty();
}