#include <bits/stdc++.h>

using namespace std;

typedef pair<int,int> P;
typedef pair<int,pair<int,int>> PP;
typedef long long ll;

const double EPS = 1e-8;
const int INF = 1e9;
const int MOD = 1e9+7;

int dy[] = {0,1,0,-1};
int dx[] = {1,0,-1,0};

int main(void) {
	int n;
	cin >> n;
	vector<int> items(10);
	int pw = 0;
	for(int i=0;i<n;i++){
		int a,b,c;
		cin >> a >> b >> c;a--;b--;c--;
		items[a]++;
		items[b]++;
		items[c]++;
	}

	int amari = 0;
	for(int i=0;i<10;i++){
		amari += items[i]%2;
		pw += items[i]/2;
	}
	cout << pw + amari/4 << endl;

	return 0;
}