package chelper;

import java.util.HashMap;
import java.util.Map;

import io.InputReader;
import io.OutputWriter;
import solutions.ChelperSolution;


public class TaskC extends ChelperSolution {

  @Override
  public void solve(int testNumber, InputReader in, OutputWriter out) {
    super.solve(testNumber, in, out);
  }

  @Override
  public void solve(int testNumber) {
    int n = in.nextInt();

    int equals = 0;
    Map<Integer, Integer> counts = new HashMap<>();

    for (int i = 0; i < n; i++) {
      String s = in.nextString();

      int balance = 0;
      int min = 0;
      for (char c : s.toCharArray()) {
        if (c == '(') {
          balance++;
        } else {
          balance--;
        }
        min = Math.min(min, balance);
      }

      if (min == 0 && balance == 0) {
        equals++;
        continue;
      }

      if ((min == 0 && balance > 0) || (min < 0 && balance == min)) {
        counts.put(balance, 1 + counts.getOrDefault(balance, 0));
      }
    }

    int res = equals / 2;
    for (Map.Entry<Integer, Integer> entry : counts.entrySet()) {
      if (entry.getKey() > 0) {
        res += Math.min(entry.getValue(), counts.getOrDefault(-entry.getKey(), 0));
      }
    }

    out.println(res);
  }
}