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

int main() {
    int N;
    cin >> N;
    vector<int> v(11);
    for (int i = 0; i < N; i++) {
        int a, b, c;
        cin >> a >> b >> c;
        v[a]++;
        v[b]++;
        v[c]++;
    }
    int res = 0;
    int ans = 0;
    for (int i = 1; i < 11; i++) {
        ans += v[i] / 2;
        res += v[i] % 2;
    }
    ans += res / 4;
    cout << res << endl;
}