You will be given four points in a 2D co-ordinate system. Find whether they form rectangle (containing sides parallel to the axis and having non-zero area ) or not.

Input:
In four lines you will be given co-ordinate of each points (x,y)

Output:
Print "YES" if they are vertices of a rectangle(as described in problem statement) else print "NO" (without quotes)

Constraints:
-10⁹ <= x,y <= 10⁹