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:
import math

def slope(x1, y1, x2, y2):
    if (x2-x1)==0:
        return "undefined"
    return (y2-y1)/(x2-x1)
def distance(x1, y1, x2, y2):
    xdiff = x2-x1;ydiff = y2-y1

    return xdiff**2 + ydiff**2

x1,x2,y1,y2,z1,z2 = map(int, input().split())

if slope(x1,x2,y1,y2) == slope(y1,y2,z1,z2) == slope(x1,x2,z1,z2):
    print('NO')
elif not(distance(x1,x2,y1,y2) == distance(y1,y2,z1,z2)):
    print("NO")
else:
    print("YES")