#include <bits/stdc++.h>
#define rep(i,n) for(int i=0;i<(n);++i)
#define ALL(A) A.begin(), A.end()

using namespace std;

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

int items[10];

int main()
{
	memset(items, 0, sizeof(items));
	ios_base::sync_with_stdio(0);
	cin.tie(0);

	int N; cin >> N;
	rep (i, N){
		int a[3] = {0};
		rep (j, 3) cin >> a[j];
		rep (j, 3) --a[j];
		rep (j, 3) ++items[a[j]];
	} // end rep

	int res = 0;
	rep (i, 10){
		res += items[i] / 2;
		items[i] -= (items[i] / 2) * 2;
	} // end rep
	
	while(true){
		bool update = true;
		int cnt = 0;
		set<int> kind; kind.clear();
		rep (i, 10){
			if (items[i] > 0 && kind.size() < 4){
				kind.insert(i);
				--items[i];
			} // end if
		} // end rep
		if (kind.size() < 4) update = false;
		if (!update) break;
		++res;
	} // end while

	cout << res << endl;

	return 0;
}