#include <bits/stdc++.h>   using namespace std;   char s[500005];   int A[500005][2];   int B[500005];   int C[500005];   int main() {     ios::sync_with_stdio(false);     int n;     memset(A, 0, sizeof(A));     memset(B, 0, sizeof(B));     memset(C, 0, sizeof(C));     cin >> n;     for (int i = 0; i < n; i++) {       cin >> s;       int len = strlen(s);       if (s[0] ==  )  && s[len - 1] ==  ( ) continue;       for (int j = 0; j < len; j++) {         if (s[j] ==  ( )           A[i][0]++;         else if (s[j] ==  )  && A[i][0] > 0)           A[i][0]--;         else           A[i][1]--;       }       if (A[i][0] >= 0 && A[i][1] == 0) C[i] = A[i][0];       if (A[i][0] == 0 && A[i][1] <= 0) C[i] = A[i][1];       if (C[i] >= 0 && (A[i][0] == 0 || A[i][1] == 0)) B[C[i]]++;     }     int ans = 0;     for (int i = 0; i < n; i++) {       if (C[i] < 0) {         int t = 0 - C[i];         if (B[t] > 0) {           ans++;           B[t]--;         }       }     }     ans += B[0] / 2;     cout << ans << endl;     return 0;   }   