#include <bits/stdc++.h>
using namespace std;

int main()
{
	int n, a, b, c;
	cin >> n;
	map<int, int> mp;
	for(int i = 0; i < n; i++)
	{
		cin >> a >> b >> c;
		if(mp.count(a)) mp.at(a)++;
		else mp[a] = 1;
		if(mp.count(b)) mp.at(b)++;
		else mp[b] = 1;
		if(mp.count(c)) mp.at(c)++;
		else mp[c] = 1;
	}
	
	int ans = 0;
	int cnt = 0;
	for(auto v : mp)
	{
		ans += v.second / 2;
		cnt += v.second % 2;
	}
	ans += cnt / 4;
	cout << ans << endl;
	return 0;
}