#include <bits/stdc++.h>

using namespace std;

#define fi first
#define se second
#define pb push_back
#define all(a) a.begin(), a.end()
#define sz(a) (int)a.size()

#define PI 3.14159265

typedef long double ld;
typedef long long ll;

const ld EPS = 1e-6;
const int MX = 2e5 + 1;
const ld INF = 7e18;

bitset<MX> b;

struct point {
    ld x, y;
    point() {};
    point(ld x, ld y) {
        this -> x = x,
        this -> y = y;
    }
    point(const point& a) {
        x = a.x,
        y = a.y;
    }
};

point p[3];

struct event {
    ld x;
    int type;
    int id;
    event() {};
    event(ld x, int type, int id) {
        this -> x = x,
        this -> type = type,
        this -> id = id;
    }
};

deque<event> a;

point rot(point a, ld alpha) {
    alpha *= PI / 180.0;
    return point(a.x * cos(alpha) - a.y * sin(alpha), a.x * sin(alpha) + a.y * cos(alpha));
}

ld get(point a, point b) {
    if (a.x == b.x) return 90.0;
    if (a.y == b.y) return 0.0;
    if (a.y < b.y) swap(a, b);
    ld sign = 1;
    if (b.x < a.x) sign = -1.0;
    ld k1 = a.y - b.y, k2 = (b.x - a.x) * sign, h = hypot(k2, k1);
    ld r = acos(k2 / h) * 180.0 / PI;
    if (sign > 0) return min(r, 180.0 - r);
    return max(r, 180.0 - r);
}

bool check(ld alpha) {
    point pt[3];
    for (int i = 0; i < 3; ++i)
        pt[i] = rot(p[i], alpha);
    //for (int i = 0; i < 3; ++i) cout << pt[i].x << " " << pt[i].y << endl;
    return (pt[0].y - pt[1].y <= EPS && pt[0].y - pt[2].y <= EPS);
}

ld rot(ld alpha) {
    if (alpha <= 180.0)
        return alpha + 180.0;
    return alpha - 180.0;
}

void solve(deque<ld>& d, int time) {
    ld l = INF, r = -INF;
    int it = 0;
    for (int i = 0; i < 4; ++i) {
        l = INF, r = -INF;
        while (it < sz(d) && check(d[it]) == 0) ++it;
        if (it == sz(d)) return;
        l = d[it];
        ++it;
        while (it < sz(d) && check(d[it]) && check((d[it - 1] + d[it]) / 2.0)) ++it;
        r = d[--it];
        a.pb(event(l, 0, time)), a.pb(event(r, 1, time));
        ++it;
        if (it == sz(d) - 1) return;
    }
}

void print(deque<event>& d) {
    for (auto &pt : d)
        cout << pt.x << " " << pt.type << " " << pt.id << endl;
    cout << endl;
}

bool cmp(event& a, event& b) {
    if (fabs(a.x - b.x) <= EPS)
        return a.type < b.type;
    return (a.x - b.x < EPS);
}

main() {
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    int n;
    cin >> n;
    for (int i = 0; i < n; ++i) {
        for (int j = 0; j < 3; ++j)
            cin >> p[j].x >> p[j].y;
        deque<ld> t;
        ld fi1 = get(p[0], p[1]), fi2 = get(p[0], p[2]);
        t.pb(fi1), t.pb(fi2);
        t.pb(rot(fi1)), t.pb(rot(fi2));
        sort(all(t));
        if (t[0] != 0.0) t.push_front(0.0);
        if (t[sz(t) - 1] != 360.0) t.pb(360.0);
        //for (auto &pt : t) cout << pt << " "; cout << '\n';
        solve(t, i);
    }
    int ans = -1, cur = 0;
    sort(all(a), cmp);
    for (auto &pt : a)
        if (pt.type == 0 && b[pt.id] == 0)
            ans = max(ans, ++cur), b[pt.id] = 1;
        else if (pt.type == 1)
            --cur, b[pt.id] = 0;
    cout << ans;
}