Arpa and an exam about geometry

题意 Arpa正在参加一场几何学考试。这是这场考试的最后一题。 给你三个点。让你找一个点和一个角度使得按这个点旋转这个角度后，a的新位置与b的原位置重合，b的新位置与c的原位置重合。 Arpa怀疑这个问题是否有解（如果存在一个点和一个角度满足条件）。请帮助Arpa确定这个问题是否有解决方案。 输入格式： 单独一行包含六个整数$a_{x},a_{y},b_{x},b_{y},c_{x},c_{y}$ 。保证给出的点是不同的。 输出格式： 如果这个问题有解决方案，输出 "Yes"，否则，输出 "No" 。 感谢@Fowany 提供的翻译

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.

The only line contains six integers $ a_{x},a_{y},b_{x},b_{y},c_{x},c_{y} $ ( $ |a_{x}|,|a_{y}|,|b_{x}|,|b_{y}|,|c_{x}|,|c_{y}|<=10^{9} $ ). It's guaranteed that the points are distinct.

Print "Yes" if the problem has a solution, "No" otherwise. You can print each letter in any case (upper or lower).

0 1 1 1 1 0

Yes

1 1 0 0 1000 1000

No

In the first sample test, rotate the page around $ (0.5,0.5) $ by . In the second sample test, you can't find any solution.