#include <iostream>
#include <algorithm>
#include <vector>
#include<string>

using namespace std;
int main(){
	int N;
	cin >> N;
	vector<int> a(N);
	vector<int> b(N);
	vector<int> c(N);
	vector<int> memo(11);
	for (int i = 0; i < N; i++) {
		cin >> a[i] >> b[i] >> c[i];
	}

	for (int i = 0; i < N; i++) {
		memo[a[i]]++;
		memo[b[i]]++;
		memo[c[i]]++;
	}
	/*for (int i = 1; i < 11; i++) {
		cout << memo[i] << endl;
	}*/

	int cnt = 0; //回数保存用
	int power = 0;
	for (int i = 1; i < 11; i++) {
		if (1<memo[i]) {
			cnt += memo[i] / 2;
			power += memo[i] % 2;
		}else if (memo[i]==1) {
			power += memo[i];
		}
	}
	cnt += power / 4;
	cout << cnt << "\n";
	return 0;
}