#include <iostream>

using namespace std;

int N, a[10];

int main() {
    cin >> N;
    int ans = 0;
    for (int i = 0; i < N; i++) {
        for (int j = 0; j < 3; j++) {
            int x;
            cin >> x;
            a[x - 1]++;
            if (a[x - 1] == 2) {
                ans++;
                a[x - 1] = 0;
            }
        }
    }
    int x = 0;
    for (int i = 0; i < 10; i++) {
        x += a[i];
        if (x == 4) {
            ans++;
            x = 0;
        }
    }
    cout << ans << endl;
    return 0;
}