#include<cstdio>
#include <iostream>
#include<algorithm>
#include<string>
#include<queue>
#include<vector>
#include<functional>
#include<cmath>
#include<map>
#include<stack>
#include<set>
#include<numeric>

using namespace std;
typedef long long ll;
typedef pair<ll, ll> Pr;

int N;
int item[11];
int sum = 0,ans = 0;

int main()
{
	cin >> N;
	for (int i = 0; i < N; i++) {
		int a, b, c;
		cin >> a >> b >> c;
		item[a]++;
		item[b]++;
		item[c]++;
		sum += 3;
	}
	for (int i = 1; i <= 10; i++) {
		if (item[i] > 1) {
			ans += item[i] / 2;
			sum -= (item[i] / 2) * 2;
		}
	}
	ans += sum / 4;
	cout << ans << endl;
	return 0;
}