#include <algorithm>
#include <iostream>
#include <iomanip>
#include <map>
#include <numeric>
#include <set>
#include <sstream>
#include <string>
#include <vector>
#include <cmath>
using namespace std;

#define FOR(i,s,e) for (int i = int(s); i != int(e); i++)
#define FORIT(i,c) for (typeof((c).begin()) i = (c).begin(); i != (c).end(); i++)
#define ISEQ(c) (c).begin(), (c).end()

int main(){
	int N;
	cin  >> N;

	int count[10];
	FOR (i,0,10) count[i] = 0;

	FOR(i,0,N){
		FOR(j,0,3){
			int t;
			cin >> t;
			count[t-1]++;
		}
	}

	int ans = 0;

	FOR(i,0,10){
		while(count[i] >= 2){
			ans++;
			count[i] -=  2;
		}
	}

	int z = 0;
	FOR(i,0,10){
		z += count[i];
	}

	ans += z/4;

	cout << ans << endl;
	return 0;

}