#include<stdio.h>
#include <vector>
#include <list>
#include <map>
#include <set>
#include <queue>
#include <stack>
#include <algorithm>
#include <sstream>
#include <iostream>
#include <string>

using namespace std;

int main() {

	int N, a, b, c, item[10] = {};
	cin >> N;
	for (int i = 0; i < N; i++) {		
		cin >> a >> b >> c;
		item[a - 1]++;
		item[b - 1]++;
		item[c - 1]++;
	}
	int sum = 0;
	for (int i = 0; i < 10; i++) {
		sum += item[i] / 2;
		item[i] %= 2;
	}
	while (1) {
		int cnt = 0;
		for (int i = 0; i < 10; i++) {
			if (item[i] > 0) {
				cnt++;
				item[i]--;
				if (cnt == 4) {
					sum++;
					break;
					cout << "4get" << endl;
				}
			}
		}
		if (cnt != 4) break;
	}

	cout << sum << endl;

	return 0;
}