#include <bits/stdc++.h>
using namespace std;
typedef long long LL;
int main()
{
#ifndef ONLINE_JUDGE
  freopen("data/data1.in", "r", stdin);
  // freopen("data/data1.out", "w", stdout);
#endif
  int n;
  string s;
  cin >> n >> s;

  LL l = 0;
  LL r = 0;

  vector<pair<LL, LL>> lr;
  LL ans = 0;
  LL C = 0;
  for (int i = 0; i < n; i++)
  {
    if (s[i] == '(')
    {
      l++;
    }
    else
    {
      if (l > 0)
      {
        l--;
        C++;
      }
      else
        r++;
    }
    lr.emplace_back(l, r);
    ans += C * 2;
  }
  sort(lr.begin(), lr.end(), [](auto a, auto b)
       { return minmax(-a.second, -a.second + a.first - b.second) > minmax(-b.second, -b.second + b.first - a.second); });
  l = 0;
  for (auto p : lr)
  {
    LL take = min(l, p.second);
    l -= take;
    ans += take * 2;
    l += p.first;
  }
  cout << ans << endl;
}