#include <iostream>
#include <algorithm>
#include <string>
#include <vector>
#include <map>
#include <set>
#include <stdio.h>
#include <cstring>
#include <queue>
#include <stack>
#include <functional>
#include <math.h>
#include <iomanip>
using namespace std;
#define Would
#define you
const int INF = 999999999;
const int MOD = 1e9 + 7;
const double pi = 3.141592653589793238;

bool used[105];
int main() {
	int n, ans = 0;
	cin >> n;
	vector<int>v;
	for (int i = 0; i < n; ++i) {
		int a, b, c;
		cin >> a >> b >> c;
		v.push_back(a), v.push_back(b), v.push_back(c);
	}
	sort(v.begin(), v.end());
	for (int i = 0; i < 3 * n - 1; ++i) {
		if (v[i] == v[i + 1] && !used[i] && !used[i + 1]) {
			used[i] = 1, used[i + 1] = 1;
			++ans;
		}
	}
	cout << ans + (3 * n - ans * 2) / 4 << endl;
}