There is a triangle formed by three points (x1,y1), (x2,y2), (x3,y3) on a plain.
Write a program which prints "YES" if a point P (xp,yp) is in the triangle and "NO" if not.
Input consists of several datasets. Each dataset consists of:
x1 y1 x2 y2 x3 y3 xp yp
All the input are real numbers. Input ends with EOF. The number of datasets is less than or equal to 100.
You can assume that:
For each dataset, print "YES" or "NO" in a line.
0.0 0.0 2.0 0.0 2.0 2.0 1.5 0.5 0.0 0.0 1.0 4.0 5.0 3.0 -1.0 3.0
YES NO