#include <vector>
#include "iostream"
#include "algorithm"
using namespace std;

int main() {
    int n,a,b,c;
    vector<int> item;
    cin>>n;
    while (n--) {
        cin>>a>>b>>c;
        item.push_back(a);
        item.push_back(b);
        item.push_back(c);
    }

    n = 0;  // answer

    sort(item.begin(),item.end());
    for (int i=0; i< item.size(); i++) {
        if (item[i] == item[i+1]) {
            n++;
            item[i] = item[i+1] = -1;
        }
    }
    item.erase(remove(item.begin(), item.end(), -1), item.end());
    n += item.size()/4;
    cout<<n<<endl;
    return 0;
}