#include <bits/stdc++.h> 

using i64 = long long; 
using u64 = unsigned long long; 
using u32 = unsigned; 

using u128 = unsigned __int128; 
using i128 = __int128; 

void solve() {
	int N; std::cin >> N;
	std::vector<int> A(10);
	for(int i = 0; i < N; i ++) {
		int a, b, c; std::cin >> a >> b >> c;
		A[a - 1] ++;
		A[b - 1] ++;
		A[c - 1] ++;
	}
	int ans = 0, z = 0;
	for(int i = 0; i < 10; i ++) {
		int a = A[i] / 2;
		ans += a;
		z += A[i] - 2 * a;
	}

	std::cout << ans + (z / 4);
} 

int main() { 
	std::ios::sync_with_stdio(false); 
	std::cin.tie(nullptr); 

	int T = 1; 
	//std::cin >> T; 

	while (T--) { 
		solve(); 
	} 
	return 0; 
}