#include <iostream>
using namespace std;

bool solve(double a1, double b1, double a2, double b2, double x, double y)
{
	if((a2-a1)*(a2-a1)+(b2-b1)*(b2-b1) > max((x-a1)*(x-a1)+(y-b1)*(y-b1),(a2-x)*(a2-x)+(b2-y)*(b2-y)))
		return true;
	return false;
}

int main()
{
	double x1,y1,x2,y2,x3,y3,xp,yp;
	while(cin >> x1 >> y1 >> x2 >> y2 >> x3 >> y3 >> xp >> yp){
		if(solve(x1,y1,x2,y2,xp,yp && solve(x2,y2,x3,y3,xp,yp) && solve(x3,y3,x1,y1,xp,yp)))
			cout << "YES" << endl;
		else
			cout << "NO" << endl;
	}
	return 0;
}