#include <iostream>
//#include<atcoder/all>
#include <numeric>
#include <cmath>
#include <limits>
#include <stdio.h>
#include <iomanip>
#include <string> 
#include <vector>
#include <algorithm>
#include <utility> 
#include <tuple> 
#include <cstdint> 
#include <cstdio> 
#include <map> 
#include <queue>
#include <set> 
#include <stack> 
#include <deque> 
#include <unordered_map> 
#include <unordered_set>
#include <bitset> 
#include <cctype>
//using namespace atcoder;
using namespace std;
using ll = long long;
#define all(A) A.begin(),A.end()
using vll = vector<ll>;
#define rep(i, n) for (long long i = 0; i < (long long)(n); i++)
using Graph = vector<vector<vector<pair<ll, ll>>>>;

int main() {
	ll N;
	cin >> N;
	vll D(11, 0);
	rep(i, N) {
		rep(k, 3) {
			ll A;
			cin >> A;
			D[A]++;
		}
	}
	ll an = 0;
	ll p = 0;
	rep(i, 11) {
		an += D[i] / 2;
		if (D[i] % 2 != 0)p++;
	}
	cout << an + p / 4 << endl;
}