#include<iostream>
#include<cstdio>
#include<algorithm>
#include<cmath>
#include<vector>
#include<iomanip>
using namespace std;
#define EPS (1e-10)
#define equals(a, b) (fabs((a) - (b)) < EPS)

class Point{
	public:
		double x, y;

		Point(double x = 0, double y = 0): x(x), y(y) {}

		Point operator + (Point p){ return Point(x + p.x, y + p.y);}
		Point operator - (Point p){ return Point(x - p.x, y - p.y);}
		Point operator * (double a){ return Point(a * x, a * y);}
		Point operator / (double a){ return Point(x / a, y / a);}

		double abs(){ return sqrt(norm());}
		double norm(){ return x * x + y * y;}

		bool operator < (const Point &p) const{
			return x != p.x ? x < p.x : y < p.y;
		}

		bool operator == (const Point &p) const{
			return fabs(x - p.x) < EPS && fabs(y - p.y) < EPS;
		}
};

struct Segment {
	Point p1, p2;
};
typedef Segment Line;

class Circle{
	public:
		Point c;
		double r;
		Circle(Point c = Point(), double r = 0.0): c(c), r(r) {}
};

typedef Point Vector;
typedef vector<Point> Polygon;

double dot(Vector a, Vector b){
	return a.x * b.x + a.y * b.y;
}
double cross(Vector a, Vector b){
	return a.x * b.y - a.y * b.x;
}

int contains(Polygon g, Point p){
	int n = g.size();
	bool x = false;
	for(int i = 0; i < n; i++){
		Point a = g[i] - p, b = g[(i + 1) % n] - p;
		if(abs(cross(a, b)) < EPS && dot(a, b) < EPS) return 1;
		if(a.y > b.y) swap(a, b);
		if(a.y < EPS && EPS < b.y && cross(a, b) > EPS) x = !x;
	}
	return (x ? 2 : 0);
}

int main(){
	int n;
	Polygon g(3); Point p;
	for(;;){
		if(!(cin >> g[0].x)) break;
		cin >> g[0].y;
		for(int i = 1; i < 3; i++){
			cin >> g[i].x >> g[i].y;
		}
		cin >> p.x >> p.y;
		if(contains(g, p) == 2) cout << "YES" << endl;
		else cout << "NO" << endl;
	}
	return 0;
}
