import copy,math,numpy
def mul(a,b):return numpy.array(a).dot(b)

def rotateTriangle(*_):
	d=copy.deepcopy(list(_))
	for i in range(len(d)-1,-1,-1):
		d[i][0]-=d[0][0]
		d[i][1]-=d[0][1]
		d[i][2]-=d[0][2]
	d=list(zip(*d))
	thetay=-math.atan2(d[2][1],d[0][1])
	d=mul([[math.cos(thetay),0,-math.sin(thetay)],[0,1,0],[math.sin(thetay),0,math.cos(thetay)]],d)
	thetaz=-math.atan2(d[1][1],d[0][1])
	d=mul([[math.cos(thetaz),-math.sin(thetaz),0],[math.sin(thetaz),math.cos(thetaz),0],[0,0,1]],d)
	thetax=-math.atan2(d[2][2],d[1][2])
	d=mul([[1,0,0],[0,math.cos(thetax),-math.sin(thetax)],[0,math.sin(thetax),math.cos(thetax)]],d)
	d=list(zip(*d))
	return [e[0:2] for e in d]

import sys
a=[list(map(float,sys.stdin.readline().split())) for _ in range(4)]
for e in a:
	assert(all(-1e6<=f<=1e6 for f in e))
b=rotateTriangle(*a)
for i in range(3):
	edgex=b[(i+1)%3][0]-b[i][0]
	edgey=b[(i+1)%3][1]-b[i][1]
	vx=b[3][0]-b[i][0]
	vy=b[3][1]-b[i][1]
	if edgex*vy-edgey*vx<0:
		print('NO')
		exit()
print('YES')