#include <bits/stdc++.h>
using namespace std;
typedef long long LL;
int n, t, L, R;
LL ans;
char s[100005];
struct node
{
  int L, R;
  bool operator<(const node &t) const
  {
    if (R == t.R)
      return L + t.R > t.L + R;
    return R < t.R;
  }
};
vector<node> p;

int main()
{
#ifndef ONLINE_JUDGE
  freopen("data/data1.in", "r", stdin);
  // freopen("data/data1.out", "w", stdout);
#endif
  scanf("%d%s", &n, s);
  for (int i = 0, t = 0; s[i]; i++)
  {
    if (s[i] == '(')
      L++;
    else
      L > 0 ? t++, L-- : R++;

    ans += t << 1;
    p.push_back({L, R});
  }
  sort(p.begin(), p.end());
  L = 0;
  for (auto &&t : p)
  {
    int p = min(L, t.R);
    L -= p;
    L += t.L;
    ans += p << 1;
  }
  cout << ans;
  return 0;
}