Problem: Arpa is taking a geometry exam. Here is the last problem of the exam.

You are given three points a, b, c.

Find a point and an angle such that if we rotate the page around the point by the angle, the new position of a is the same as the old position of b, and the new position of b is the same as the old position of c.

Arpa is doubting if the problem has a solution or not (i.e. if there exists a point and an angle satisfying the condition). Help Arpa determine if the question has a solution or not.

Input

The only line contains six integers ax, ay, bx, by, cx, cy (|ax|, |ay|, |bx|, |by|, |cx|, |cy| ≤ 109). It's guaranteed that the points are distinct.

Output

Print "Yes" if the problem has a solution, "No" otherwise.

You can print each letter in any case (upper or lower).

Examples

Input

0 1 1 1 1 0


Output

Yes


Input

1 1 0 0 1000 1000


Output

No

Note

In the first sample test, rotate the page around (0.5, 0.5) by <image>.

In the second sample test, you can't find any solution.

Solution (in PYTHON3):

Solution:
ax, ay, bx, by, cx, cy = [int(i) for i in input().split()]

l1 = (ax-bx)*(ax-bx)+(ay-by)*(ay-by)
l2 = (ax-cx)*(ax-cx)+(ay-cy)*(ay-cy)
l3 = (bx-cx)*(bx-cx)+(by-cy)*(by-cy)

if(((ax * (by - cy)) + (bx * (cy - ay)) + (cx * (ay - by)) != 0) and (l1 == l2 or l1 == l3)):
    print("yes")
else:
    print("no")