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 const N = 1000020;
double m(double ax, double ay, double bx, double by) {
  if (ax - bx == 0) return 1.0;
  return (by - ay) / (bx - ax);
}
double d(long long ax, long long ay, long long bx, long long by) {
  return (ax - bx) * (ax - bx) + (by - ay) * (by - ay);
}
double const EPS = 1e-12;
int main() {
  ios_base::sync_with_stdio(false), cin.tie(0), cout.tie(0);
  int ax, ay, bx, by, cx, cy;
  cin >> ax >> ay >> bx >> by >> cx >> cy;
  if (fabs(m(ax, ay, bx, by) - m(bx, by, cx, cy)) > EPS and
      d(ax, ay, bx, by) == d(bx, by, cx, cy))
    cout << "YES\n";
  else
    cout << "NO\n";
  return 0;
}