#include <bits/stdc++.h>

[[nodiscard]] static inline constexpr uint_fast32_t solve([[maybe_unused]] const uint_fast32_t N, const std::vector<std::array<uint_least32_t, 3>>& drops) noexcept
{
	std::array<uint_fast32_t, 11> count_of = { 0, };
	for (const auto& [a, b, c] : drops)
		++count_of[a], ++count_of[b], ++count_of[c];

	uint_fast32_t ans = 0;
	for (auto& c : count_of)
		ans += c / 2, c %= 2;

	return ans + std::accumulate(count_of.begin(), count_of.end(), UINT32_C(0)) / 4;
}

int main()
{
	std::cin.tie(nullptr);
	std::ios::sync_with_stdio(false);
	
	uint_fast32_t N;
	std::cin >> N;
	std::vector<std::array<uint_least32_t, 3>> drops(N);
	for (auto& [a, b, c] : drops) std::cin >> a >> b >> c;

	std::cout << solve(N, drops) << '\n';
	return 0;
}