#include <bits/stdc++.h>

using namespace std;

int main(void) {
  int n;
  cin >> n;

  map<int, int> mp;
  for (int i = 0; i < n; i++) {
    int a, b, c;
    cin >> a >> b >> c;
    mp[a]++;
    mp[b]++;
    mp[c]++;
  }

  int ans = 0, rem = 0;
  for (auto i : mp) {
    ans += i.second / 2;
    rem += i.second % 2;
  }
  ans += rem / 4;

  cout << ans << endl;

  return 0;
}