#include <iostream>

size_t parse (size_t from, const std::string& str) {
    int sum = 0;
    for (size_t i = from; i < str.size(); i++) {
        if(str[i] == '(') {
            sum++;
        } else {
            sum--;
        }
        if (sum == 0)
            return i;
    }
    //std::cout << "wtf" << std::endl;
    //std::cout << "parse: " << from << std::endl;
    return 0;
}

size_t evaluate(size_t from, size_t to, const std::string& str) {
    //std::cout << "evaluate(" << from << ", " << to << "...)" << std::endl;
    size_t counter = 0;
    from++;
    while (from < to) {
        size_t from2 = parse(from, str);
        //std::cout << "evaluate: " << from2 << std::endl;
        if (counter == 0)
            counter = 1;
        counter *= evaluate(from, from2, str);
        from = from2 + 1;
    }
    return counter+1;
}


int main() {

    int num;
    std::cin >> num;
    std::string exp;
    std::getline(std::cin, exp);
    std::getline(std::cin, exp);
    size_t res = evaluate(0, num - 1, exp);
    std::cout <<res << std::endl;

    return 0;
}