#include <bits/stdc++.h>
using namespace std;
#pragma GCC optimize("-O3")
using ld = long double;
const long long int mod = 1000000007;
const long long int inf = 1000000000000000000;
const long long int rk = 256;
const ld PI = 3.141592653589793;
ostream& operator<<(ostream& os, pair<long long int, long long int> const& x) {
  os << x.first << "," << x.second;
  return os;
}
template <class T>
ostream& operator<<(ostream& os, vector<T> const& x) {
  os << "{ ";
  for (auto& y : x) os << y << " ";
  return os << "}";
}
template <class T>
ostream& operator<<(ostream& os, set<T> const& x) {
  os << "{ ";
  for (auto& y : x) os << y << " ";
  return os << "}";
}
template <class Ch, class Tr, class Container>
basic_ostream<Ch, Tr>& operator<<(basic_ostream<Ch, Tr>& os,
                                  Container const& x) {
  os << "{ ";
  for (auto& y : x) os << y << " ";
  return os << "}";
}
template <class X, class Y>
ostream& operator<<(ostream& os, pair<X, Y> const& p) {
  return os << "[ " << p.first << ", " << p.second << "]";
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  long long int t;
  cin >> t;
  map<long long int, long long int> d;
  long long int ans = 0;
  while (t--) {
    string s;
    cin >> s;
    long long int cnt1 = 0, cnt2 = 0;
    for (long long int i = 0; i < s.size(); i++) {
      if (s[i] == '(')
        cnt1 += 1;
      else {
        if (cnt1 > 0)
          cnt1--;
        else
          cnt2 += 1;
      }
    }
    if (cnt1 == 0 && cnt2 > 0) {
      if (d[cnt2] > 0) {
        d[cnt2] -= 1;
        ans += 1;
      } else {
        d[-cnt2]++;
      }
    } else if (cnt1 > 0 && cnt2 == 0) {
      if (d[-cnt1] > 0) {
        d[-cnt1] -= 1;
        ans++;
      } else
        d[cnt1] += 1;
    } else if (cnt1 == 0 && cnt2 == 0) {
      if (d[0] > 0) {
        ans++;
        d[0] -= 1;
      } else
        d[0]++;
    }
  }
  cout << ans << '\n';
  return 0;
}
