#include <stdio.h>
#include <stdlib.h>


float area(float x1, float y1, float x2, float y2, float x3, float y3)
{
   return abs((x1*(y2-y3) + x2*(y3-y1)+ x3*(y1-y2))/2.0);
}


bool isInside(int x1, int y1, int x2, int y2, int x3, int y3, int x, int y)
{
   /* Calculate area of triangle ABC */
   float A = area (x1, y1, x2, y2, x3, y3);

   /* Calculate area of triangle PBC */
   float A1 = area (x, y, x2, y2, x3, y3);

   /* Calculate area of triangle PAC */
   float A2 = area (x1, y1, x, y, x3, y3);

   /* Calculate area of triangle PAB */
   float A3 = area (x1, y1, x2, y2, x, y);

   /* Check if sum of A1, A2 and A3 is same as A */
   return (A == A1 + A2 + A3);
}

int main()
{

   float x1,x2,x3,x4,x5,x6,x7,x8;
   while(scanf("%f%f%f%f%f%f%f%f",&x1,&x2,&x3,&x4,&x5,&x6,&x7,&x8)==8)
   {
       if (isInside(x1,x2,x3,x4,x5,x6,x7,x8))
     printf ("YES\n");
   else
     printf ("NO\n");

   }


   return 0;
}