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;
template <typename T, typename U>
inline void chmin(T &x, U y) {
  if (y < x) x = y;
}
const long long oo = 1e9 + 7;
int ax, ay, bx, by, cx, cy;
int main() {
  cin >> ax >> ay >> bx >> by >> cx >> cy;
  int check1 = 0, check2 = 1;
  long long d1 = 1LL * (ax - bx) * (ax - bx) + 1LL * (ay - by) * (ay - by);
  long long d2 = 1LL * (bx - cx) * (bx - cx) + 1LL * (by - cy) * (by - cy);
  if (d1 == d2) check1 = 1;
  if (bx == double(ax + cx) / 2 && by == double(ay + cy) / 2) check2 = 0;
  if (ax == double(bx + cx) / 2 && ay == double(by + cy) / 2) check2 = 0;
  if (cx == double(ax + bx) / 2 && cy == double(ay + by) / 2) check2 = 0;
  if (check1 && check2)
    cout << "yes";
  else
    cout << "no";
}