#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; }