#!/usr/bin/python
#works with Py2/3 and use numpy only if available.

import copy,math
try:
    import numpy
    def mul(a,b):
        return numpy.array(a).dot(b)
except ImportError:
    def mul(a,b):
        assert len(a[0])==len(b)
        r=[[0]*len(b[0]) for _ in a]
        for i in range(len(a)):
            for j in range(len(b[0])):
                for k in range(len(a[0])):
                    r[i][j]+=a[i][k]*b[k][j]
        return r

#def dist(a,b):
#    return math.sqrt(sum((a[i]-b[i])**2 for i in range(len(a))))

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)]
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')