#include<iostream>
#include<cmath>
#include<algorithm>
#include<utility>
using namespace std;
double x,y;
bool C(double a,double b,double c,double d,double e,double f)
{
	pair<double,int>p[3];
	p[0]=make_pair(atan2(d-b,c-a),0);
	p[1]=make_pair(atan2(f-b,e-a),1);
	p[2]=make_pair(atan2(y-b,x-a),2);
	sort(p,p+3);
	return p[1].second==2;
}
int main()
{
	double a,b,c,d,e,f;
	for(;cin>>a>>b>>c>>d>>e>>f>>x>>y;)
	{
		cout<<(C(a,b,c,d,e,f)&&C(c,d,e,f,a,b)&&C(e,f,a,b,c,d)?"YES":"NO")<<endl;
	}
}

