#include <string>
#include <vector>

int nesting(const std::string& s)
{
    if (s.empty()) {
        return 1;
    }

    std::vector<char> stack;
    for (char c : s) {
        if (c == ')') {
            if (stack.empty() || stack.back() != '(') {
                return 0;
            }
            stack.pop_back();
        } else {
            stack.push_back(c);
        }
    }

    return stack.empty() ? 1 : 0;
}