#include <cstdio>
#include <cstdlib>
#include <algorithm>
#include <vector>
#include <map>


using namespace std;

struct st{
	int x,y;
	st(int x,int y):x(x),y(y){}
};
int main(){ /*
	int b,n,c[11];scanf("%d%d",&b,&n);
	long long ans=0,sum=0,ave=0; 
	for(int i=0;i<n;i++){
		scanf("%d",&c[i]);
		sum+=c[i];
	}
	sum+=b;
	ave*/
	int x[6],y[6];vector<st> vs;for(int i=0;i<5;i++){scanf("%d%d",&x[i],&y[i]);vs.push_back(st(x[i],y[i]));}
	vector<st> v;
	sort(vs.begin(),vs.end(),[](st a,st b){if(a.x==b.x)return a.y<b.y;return a.x<b.x;});
	v.push_back(vs[0]);v.push_back(vs[1]);
	vs.erase(vs.begin());vs.erase(vs.begin()+1);
	sort(vs.begin(),vs.end(),[](st a,st b){if(a.y==b.y)return a.x<b.x;return a.y<b.y;});
	v.push_back(vs[0]);v.push_back(vs[1]);v.push_back(vs[2]);
	
	bool b=1;
	for(int i=0;i<5;i++){
		int ax=0,ay=0,bx=v[(i+2)%5].x-v[i].x,by=v[(i+2)%5].y-v[i].y;
		if(ax*by-ay*bx<0);
		else{b=0;break;}
	}
	if(b)printf("YES\n");
	else printf("NO\n");
	return 0;
}