#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

int main() {
    int n;
    vector<int> v;
    
    cin >> n;
    
    for (int i = 0; i < n; i++) {
        int item1, item2, item3;
        
        cin >> item1 >> std::ws >> item2 >> std::ws >> item3;
        v.push_back(item1);
        v.push_back(item2);
        v.push_back(item3);
    }
    
    sort(v.begin(), v.end());
    v.push_back(0);
    
    vector<int> v_s;
    int ct = 0;
    for (int j = 0; j < v.size() - 1; j++) {
        if (v.at(j) == v.at(j + 1)) {
            ct++;
            j++;
        } else {
            v_s.push_back(v.at(j));
        }
    }
    
    ct += v_s.size() / 4;
    
    cout << ct << endl;
    
    return 0;
}