#include <bits/stdc++.h>
using namespace std;
long long mod = 1000000007;
long long mod2 = 998244353;
long long mod3 = 1000003;
long long mod4 = 998244853;
long long inf = 1000000000000000000;
double pi = acos(-1.0);
int dh[4] = {1, -1, 0, 0};
int dw[4] = {0, 0, 1, -1};
int ddh[8] = {-1, -1, -1, 0, 0, 1, 1, 1};
int ddw[8] = {-1, 0, 1, -1, 1, -1, 0, 1};
long long lmax(long long a, long long b) {
  if (a < b)
    return b;
  else
    return a;
}
long long lmin(long long a, long long b) {
  if (a < b)
    return a;
  else
    return b;
}
long long gcd(long long a, long long b) {
  if (a < b) swap(a, b);
  if (b == 0) return a;
  if (a % b == 0) return b;
  return gcd(b, a % b);
}
long long Pow(long long n, long long k) {
  long long ret = 1;
  long long now = n;
  while (k > 0) {
    if (k & 1) ret *= now;
    now *= now;
    k /= 2;
  }
  return ret;
}
long long beki(long long n, long long k, long long md) {
  long long ret = 1;
  long long now = n;
  while (k > 0) {
    if (k % 2 == 1) {
      ret *= now;
      ret %= md;
    }
    now *= now;
    now %= md;
    k /= 2;
  }
  return ret;
}
long long gyaku(long long n, long long md) { return beki(n, md - 2, md); }
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n;
  cin >> n;
  int a[n];
  int sum[500001];
  int sum2[500001];
  fill(sum, sum + 500001, 0);
  fill(sum2, sum2 + 500001, 0);
  for (long long i = 0; i < n; i++) {
    string s;
    cin >> s;
    a[i] = 0;
    int m = s.size();
    if (s[0] == ')') {
      if (s[m - 1] == '(') {
        a[i] = 1000000000;
        continue;
      }
      int cnt = 0;
      for (long long j = m - 1; j >= 0; j--) {
        if (s[j] == '(')
          cnt--;
        else
          cnt++;
        if (cnt < 0) {
          a[i] = 1000000000;
          break;
        }
      }
      if (a[i] != 0) continue;
      a[i] = -cnt;
      sum2[-a[i]]++;
    } else if (s[m - 1] == '(') {
      int cnt = 0;
      for (long long j = 0; j < m; j++) {
        if (s[j] == ')')
          cnt--;
        else
          cnt++;
        if (cnt < 0) {
          a[i] = 1000000000;
          break;
        }
      }
      if (a[i] != 0) continue;
      a[i] = cnt;
      sum[a[i]]++;
    } else {
      int cnt = 0;
      int mi = 0, ma = 0;
      for (long long j = 0; j < m; j++) {
        if (s[j] == ')')
          cnt--;
        else
          cnt++;
        mi = min(mi, cnt);
      }
      cnt = 0;
      for (long long j = m - 1; j >= 0; j--) {
        if (s[j] == '(')
          cnt--;
        else
          cnt++;
        ma = min(ma, cnt);
      }
      if (ma != 0 && mi != 0) continue;
      if (ma < 0)
        sum[-ma]++;
      else
        sum2[-mi]++;
    }
  }
  int ans = 0;
  for (long long i = 1; i < 500001; i++) ans += min(sum[i], sum2[i]);
  ans += (sum[0] + sum2[0]) / 2;
  cout << ans << endl;
}
