#include <stdio.h>
 
int main() {
	double xa, ya, xb, yb, xc, yc, xd, yd;
	scanf ("%lf%lf", &xa, &ya); // читаем координаты точки A
	scanf ("%lf%lf", &xb, &yb); // читаем координаты точки D
	scanf ("%lf%lf", &xc, &yc); // читаем координаты точки C
	scanf ("%lf%lf", &xd, &yd); // читаем координаты точки D
	printf (
	(((xd - xa)*(yb-ya)-(yd-ya)*(xb-xa))*((xc - xa)*(yb-ya)-(yc-ya)*(xb-xa)) >= 0) &&
	(((xd - xb)*(yc-yb)-(yd-yb)*(xc-xb))*((xa - xb)*(yc-yb)-(ya-yb)*(xc-xb)) >= 0) &&
	(((xd - xc)*(ya-yc)-(yd-yc)*(xa-xc))*((xb - xc)*(ya-yc)-(yb-yc)*(xa-xc)) >= 0 )? 
	"yes": "no");
	return 0;
}

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MAkwCTIJMAkwCTIJNQk1CjAJMAkyCTAJMAkyCTEJMQotMQktMQkxCS0xCTAJMQkwCTAKLTEJLTEJMQktMQkwCTEJMQkzCi0xCS0xCTEJLTEJMAkxCTAuNQkwCi0xCS0xCTEJLTEJMAkxCTAJMQotMgktMgkxCS0xCTAJMQkwCTAKLTEJLTEJMQktMQkwCTEJMgky

0	0	2	0	0	2	5	5
0	0	2	0	0	2	1	1
-1	-1	1	-1	0	1	0	0
-1	-1	1	-1	0	1	1	3
-1	-1	1	-1	0	1	0.5	0
-1	-1	1	-1	0	1	0	1
-2	-2	1	-1	0	1	0	0
-1	-1	1	-1	0	1	2	2