#include <bits/stdc++.h>

using namespace std;

int main() {
    while(true) {
        int N;
        cin >> N;
        if(cin.eof()){
            return 0;
        }
        string newString;
        char nextChar;
        char prevChar;
        cin >> prevChar;
        // create new string - no need for online
        for(int i = 1; i < N; i++){
            newString += prevChar;
            cin >> nextChar;
            if(prevChar == '('){
                if(nextChar == ')'){
                    newString += "1";
                }
            } else {
                if(nextChar == ')'){
                    newString += "+1";
                } else {
                    newString += "+";
                }
            }
            prevChar = nextChar;
        }
        newString += prevChar;
        stack<char> ops;
        stack<int> values;
        unordered_map<char, int> PRIORITY;
        PRIORITY['('] = 1;
        PRIORITY[')'] = 2;
        PRIORITY['+'] = 3; // 10 ((())(()))
        for(const auto &c : newString){
            if(c != '1'){
                while(c != '(' && !ops.empty() && PRIORITY[ops.top()] >= PRIORITY[c]){
                    auto right = values.top();
                    values.pop();
                    auto left = values.top();
                    values.pop();
                    ops.pop();
                    values.push(left + right);
                }
                if(c == ')'){
                    ops.pop();
                } else {
                    ops.push(c);
                }
            } else {
                values.push(1);
            }
        }
        cout << values.top() << endl;
    }
    return 0;
}