#include <iostream>
#include <vector>

auto main() -> int {
	int level = 0;
	std::vector<int> counts(10);

	int n;
	std::cin >> n;

	int a, b, c;
	for (int i = 0; i < n; ++i) {
		std::cin >> a >> b >> c;
		counts[a-1]++;
		counts[b-1]++;
		counts[c-1]++;
	}

	for (int i = 0; i < 10;) {
		if (counts[i] >= 2) {
			counts[i]--;
			counts[i]--;
			level++;
			continue;
		}
		i++;
	}

	int count4 = 0;
	for (int i = 0; i < 10;) {
		if (counts[i] >= 1) {
			counts[i]--;
			count4++;
			if (count4 == 4) {
				count4 = 0;
				level++;
			}
			continue;
		}
		i++;
	}

	std::cout << level << std::endl;
}