#include <iostream>
#include <vector>
#include <string>
#include <array>
#include <queue>
#include <deque>
#include <set>
#include <list>
#include <map>
#include <stack>
#include <utility>
#include <algorithm>
#include <numeric>
#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <cctype>
#include <cstring>
#include <climits>
#include <bitset>
#include <random>
#include <functional>
#include <sstream>
#include <iomanip>

using namespace std;

#define _CRT_SECURE_NO_WARNINGS
#define REP(i, n) for(int i=0; i<(n); i++)
#define FOR(i, m, n) for(int i=(m);i<(n);i++)
#define SZ(x) ((int)(x).size())
#define ALL(x) (x).begin(),(x).end()
#define SORT(x) sort((x).begin(),(x).end())
#define REVE(x) reverse((x).begin(),(x).end())
#define MP make_pair
#define PB push_back

typedef vector<int> VI;
typedef vector<string> VS;
typedef vector<vector<int>> VVI;
typedef pair<int, int> PII;
typedef long long LL;

int main(){
	int n;
	cin >> n;
	VI a, c;
	REP(i, n) {
		int x, y, z;
		cin >> x >> y >> z;
		a.PB(x);
		a.PB(y);
		a.PB(z);
	}

	SORT(a);
	int i = 0, ans = 0;
	while (i < n * 3) {
		int elem = a[i], cnt = 0;
		while (i < n * 3 && a[i] == elem) { cnt++; i++; }
		//cout << elem << "は" << cnt << "個\n";
		c.PB(cnt);
	}
	REP(i, SZ(c)) {
		//cout << "c[" << i << "]=" << c[i] << endl;
		ans += c[i] / 2;
		c[i] %= 2;
	}
	ans += accumulate(ALL(c), 0) / 4;
	cout << ans << endl;
}