#include <bits/stdc++.h>
using namespace std;
#define rep(i , a, b) for(int i = a; i < (b) ; ++i)
#define all(x) std::begin(x), std::end(x)
#define sz(x) ((int) x.size())
typedef long long ll;
#define int ll
typedef pair<int,int> pii;

typedef vector<int> vi;


signed main() {
    cin.tie(0)->sync_with_stdio(0);

    int n;
    int res = 0;
    cin >> n;
    for (int i = 0; i < n; ++i) {
        char sym;
        cin >> sym;
        res += sym == ')';
    }
    cout << res << endl;
    return 0;
}