#include <bits/stdc++.h>
using namespace std;
int main() {
  double ax, ay, bx, by, cx, cy;
  cin >> ax >> ay >> bx >> by >> cx >> cy;
  double p = ax - bx;
  double q = ay - by;
  double r = bx - cx;
  double s = by - cy;
  if (p / q == r / s) {
    cout << "no";
    return 0;
  }
  double ans = (ax - bx) * (ax - bx) + (ay - by) * (ay - by) -
               (cx - bx) * (cx - bx) - (cy - by) * (cy - by);
  if (ans == 0)
    cout << "yes";
  else
    cout << "no";
}
