#include <iostream>
using namespace std;

int main(void) {
	double x[4], y[4];
	double px, py;

	while(!cin.eof()) {
		bool l, r;
		l = r = false;
		cin >> x[0] >> y[0] >> x[1] >> y[1] >> x[2] >> y[2] >> px >> py;
		x[3] = x[0];
		y[3] = y[0];

		for(int i = 0; i < 3; i++) {
			if(x[i]*py - y[i]*px < 0)
				r = true;
			else
				l = true;
		}

		cout << (r ^ l ? "NO" : "YES") << endl;
	}
	return 0;

}