#include <stdio.h>
#include <stdlib.h>
/* run this program using the console pauser or add your own getch, system("pause") or input loop */
int main(int argc, char *argv[]) {
float a,b,c,d,e,f,g,h,f1,f2;
printf("a,b,c,d,e,f,g,h,\n");
scanf("%f%f%f%f%f%f%f%f", &a,&b, &c, &d, &e, &f, &g, &h);
f1=(a-e)*(h-f)-(b-f)*(g-e);
scanf ("(a-e)*(h-f)-(b-f)*(g-e)=%f", f1 );
f2=(c-e)*(h-f)-(d-f)*(g-e);
scanf("(c-e)*(h-f)-(d-f)*(g-e)=%f", f2 );
if ((f1>0) && (f2>0))
{printf("Yes");}
else if ((f1<0) && (f2<0))
{printf("Yes");}
else
{printf("NO");}
return 0;
}