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 CPP):

Solution:
#include <bits/stdc++.h>
using namespace std;
int main() {
  long double a, b, c, d, e, f, x, y;
  cin >> a >> b >> c >> d >> e >> f;
  if (c - a == 0)
    x = 10e9 + 7;
  else
    x = (d - b) / (c - a);
  if (e - c == 0)
    y = 10e9 + 7;
  else
    y = (f - d) / (e - c);
  if (x == y) {
    cout << "No";
    return 0;
  }
  x = sqrt(pow(d - b, 2) + pow(c - a, 2)),
  y = sqrt(pow(f - d, 2) + pow(e - c, 2));
  if (x != y) {
    cout << "No";
    return 0;
  }
  cout << "Yes";
  return 0;
}