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:
def dis(ax,ay,bx,by):
    return abs(ax-bx)*abs(ax-bx) + abs(ay-by)*abs(ay-by)

ar=map(int,raw_input('').split())
ax=ar[0]
ay=ar[1]
bx=ar[2]
by=ar[3]
cx=ar[4]
cy=ar[5]

if (cy-by)*(bx-ax)==(by-ay)*(cx-bx) or dis(ax,ay,bx,by)!=dis(bx,by,cx,cy):
    print 'No'
else:
    print 'Yes'