#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx")
#pragma GCC optimize 03
#pragma GCC optimize("unroll-loops")

#include <iostream>
#include <iomanip>
#include <algorithm>
#include <iterator>
#include <cmath>
#include <ctime>
#include <vector>
#include <deque>
#include <queue>
#include <set>
#include <map>
#include <stack>
#include <string>
#include <random>
#include <numeric>
#include <unordered_set>

typedef long long ll;
typedef long double lb;

#define fast ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
#define file_in freopen("input.txt", "r", stdin);
#define file_in_out freopen("cutting.in", "r", stdin); freopen("cutting.out", "w", stdout);
#define mp make_pair
#define all(x) (x).begin(), (x).end()
#define fi first
#define se second

using namespace std;

const lb pi = atan2((lb)0, (lb)-1);

struct point {
    ll x, y;

    point() {
        x = 0; y = 0;
    }

    point(ll _x, ll _y) {
        x = _x; y = _y;
    }
};

struct vec {
    ll x, y;
    lb mod;
    vec(point p1, point p2) {
        x = p2.x - p1.x;
        y = p2.y - p1.y;
        mod = sqrt(x * x + y * y);
    }
};

istream& operator>>(istream& in, point& p) {
    cin >> p.x >> p.y;
    return in;
}

ostream& operator<<(ostream& out, point& p) {
    cout << p.x << " " << p.y;
    return out;
}

ll scalar(vec v1, vec v2) {
    return v1.x * v2.x + v1.y * v2.y;
}

ll crossv(vec v1, vec v2) {
    return v1.x * v2.y - v1.y * v2.x;
}

ll sign(ll n) {
    if (n == 0) {
        return n;
    } else {
        return n / abs(n);
    }
}

int main() {
    fast
    // file_in
//  file_in_out

    point A, O, B, P;
    cin >> A >> O >> B >> P;
    vec v1(O, P), v2(O, A), v3(O, B);

    ll cr1 = sign(crossv(v1, v2));
    ll cr2 = sign(crossv(v1, v3));

    if (cr1 * cr2 <= 0) {
        if (acos(scalar(v1, v2) / (v1.mod * v2.mod)) <= pi / 2 || acos(scalar(v1, v3) / (v1.mod * v3.mod)) <= pi / 2) {
            cout << "YES" << "\n";
        } else {
            cout << "NO" << "\n";
        }
    } else {
        cout << "NO" << "\n";
    }
    return 0;
}