#include <iostream>
#include <cmath>
using namespace std;

double Area(double* x1, double* y1, double* x2, double* y2){
  return (*x1 * *y2 - *x2 * *y1)/2.0;
}

double Segitiga(double* a, double * b, double* c, double* d, double* e, double* f){
  return abs (Area(a,b,c,d) + Area(c,d,e,f) + Area(e,f,a,b));
}

int main(){
  double a, b, c, d, e, f, g, h, ta, tb;
  cin >> a >> b >> c >> d >> e >> f >> g >> h;
  ta = Segitiga(&a, &b, &c, &d, &e, &f);
  tb = Segitiga(&a, &b, &c, &d, &g, &h) + Segitiga(&a, &b, &e, &f, &g, &h) + Segitiga(&c, &d, &e, &f, &g, &h);

  if(tb > ta)
    cout << "NO\n";
  else
    cout << "YES\n";
  
return 0;
}