#include <iostream>
#include <map>

using namespace std;

int main(int argc, const char* argv[])
{
	int N;
	cin >> N;
	map<int, int> m;
	for (int i = 0; i < N; i++) {
		int a, b, c;
		cin >> a >> b >> c;
		m[a]++;
		m[b]++;
		m[c]++;
	}
	int cnt	= 0;
	int others = 0;
	for (auto&& v : m) {
		cnt += v.second / 2;
		others += v.second % 2;
	}
	cout << cnt + others / 4 << endl;
	return 0;
}