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 PYTHON):

Solution:
import sys

def solve(ax, ay, bx, by, cx, cy):
    success = (bx - ax)**2 + (by - ay)**2 == (cx - bx)**2 + (cy- by)**2
    area = (ax * by) + (bx * cy) + (cx * ay) - (ay * bx) - (by * cx) - (cy * ax)
    if success and area != 0:
        return "YES"
    else:
        return "NO"

if __name__ == "__main__":
    ax, ay, bx, by, cx, cy = map(int, sys.stdin.readline().split())
    print solve(ax, ay, bx, by, cx, cy)