#include <bits/stdc++.h>
using namespace std;

int main()
{
    int n;
    cin >> n;
    vector<int> v;
    int d[11];
    int point = 0;
    int sum = 0;
    for (int i = 0; i < 11; i++)
    {
        d[i] = 0;
    }
    for (int i = 0; i < n; i++)
    {
        int a, b, c;
        cin >>a>> b >> c;
        v.push_back(a);
        v.push_back(b);
        v.push_back(c);
    }
    for (auto &i : v)
        d[i]++;
    for (auto &i : d)
    {
        point += i / 2;
        i %= 2;
    }
    // cout<<point<<endl;
    // for(auto &i:v){
    //     cout<<i<<endl;
    // }
    for (auto &i : d)
    {
        sum += i;
    }
    point += sum / 4;
    cout << point << endl;
    // system("pause");
}