#include <iostream>
#include <vector>
#include <string>
#include <cstring>
#include <math.h>
#include <cmath>
#include <limits.h>
#include <map>
#include <set>
#include <queue>
#include <algorithm>
#include <functional>
#include <stdio.h>
using namespace std;

long long MOD = 1000000007;

int main() {
    
    int X[10] = {0};
    int N;
    cin >> N;
    for ( int i = 0; i < N; i++ ) {
        int a,b,c;
        cin >> a >> b >> c;
        X[--a]++;
        X[--b]++;
        X[--c]++;
    }
    int ans = 0;
    int count = 0;
    for ( int i = 0; i < 10; i++ ) {
        if ( X[i]%2 ) { count++; }
        ans += X[i]/2;
    }
    
    cout << ans + count/4 << endl;
    
    return 0;
}