#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
using P = pair<int, int>;
using vi = vector<int>;
using vvi = vector<vector<int>>;
using vll = vector<ll>;
using vvll = vector<vector<ll>>;
const double eps = 1e-10;
const int MOD = 1000000007;
const int INF = 1000000000;
const ll LINF = 1ll<<50;
template<typename T>
void printv(const vector<T>& s) {
  for(int i=0;i<(int)(s.size());++i) {
    cout << s[i];
    if(i == (int)(s.size())-1) cout << endl;
    else cout << " ";
  }
}
int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  cout << fixed << setprecision(10);
  string s; cin >> s;
  int n = (int)(s.size());
  int pos = 0;
  for(int i=0;i<n;++i) {
    if(s[i] == '*') {
      pos = i;
      break;
    }
  }
  stack<char> st;
  for(int i=pos+1;i<n;++i) {
    if(st.empty()) {
      st.push(s[i]);
    } else if(st.top() == '(') {
      if(s[i] == '(') st.push(s[i]);
      else st.pop();
    } else {
      st.push(s[i]);
    }
  }
  cout << (int)(st.size()) << endl;
}

