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#include <cstdio>
#include <iostream>
#include <algorithm>

using namespace std;

struct vect {
    int x, y;

    void read() {
        cin >> x >> y;
    }

    vect() {}

    vect(int a, int b) {
        x = a, y = b;
    }
};

vect operator - (vect a, vect b) {
    return vect(a.x - b.x, a.y - b.y);
}

int operator * (vect a, vect b) {
    return a.x * b.y - a.y * b.x;
}

vect v[5];

int main() {
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);

    int n, res = 0, sum, s;
    cin >> n;

    for (int i = 0; i < n; i++) {

        sum = s = 0;
        vect p;
        p.read();
        for (int j = 0; j < 4; j++)
            v[j].read();
        v[4] = v[0];

        for (int j = 0; j < 4; j++)
            sum += abs((v[j] - p) * (v[j + 1] - p));

        p = v[0];
        for (int j = 0; j < 4; j++)
            s += abs((v[j] - p) * (v[j + 1] - p));

        if (s == sum) res++;
    }

    cout << res;

    return 0;
}