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;
inline int lowbit(int x) { return x & (-x); }
inline int read() {
  int X = 0, w = 0;
  char ch = 0;
  while (!isdigit(ch)) {
    w |= ch == '-';
    ch = getchar();
  }
  while (isdigit(ch)) X = (X << 3) + (X << 1) + (ch ^ 48), ch = getchar();
  return w ? -X : X;
}
template <typename A, typename B, typename C>
inline A fpow(A x, B p, C lyd) {
  A ans = 1;
  for (; p; p >>= 1, x = 1LL * x * x % lyd)
    if (p & 1) ans = 1LL * x * ans % lyd;
  return ans;
}
inline int gcd(int a, int b) { return b ? gcd(b, a % b) : a; }
inline int lcm(int a, int b) { return a / gcd(a, b) * b; }
template <typename T>
inline T max(T x, T y, T z) {
  return max(max(x, y), z);
}
template <typename T>
inline T min(T x, T y, T z) {
  return min(min(x, y), z);
}
const double pi = acos(-1.0);
const double eps = 1e-8;
const int maxn = 1e6 + 10;
const int maxp = 1010;
const long long INF = 0x3f3f3f3f;
const int inf = 0x3f3f3f3f;
const int mod = 998244353;
int sgn(double x) {
  if (fabs(x) < eps) return 0;
  if (x < 0)
    return -1;
  else
    return 1;
}
inline double sqr(double x) { return x * x; }
struct Point {
  double x, y;
  Point() {}
  Point(double _x, double _y) {
    x = _x;
    y = _y;
  }
  void input() { scanf("%lf%lf", &x, &y); }
  void output() { printf("%.2f %.2f\n", x, y); }
  bool operator==(Point b) const {
    return sgn(x - b.x) == 0 && sgn(y - b.y) == 0;
  }
  bool operator<(Point b) const {
    return sgn(x - b.x) == 0 ? sgn(y - b.y) < 0 : x < b.x;
  }
  Point operator-(const Point &b) const { return Point(x - b.x, y - b.y); }
  double operator^(const Point &b) const { return x * b.y - y * b.x; }
  double operator*(const Point &b) const { return x * b.x + y * b.y; }
  double len() { return hypot(x, y); }
  double len2() { return x * x + y * y; }
  double distance(Point p) { return hypot(x - p.x, y - p.y); }
  Point operator+(const Point &b) const { return Point(x + b.x, y + b.y); }
  Point operator*(const double &k) const { return Point(x * k, y * k); }
  Point operator/(const double &k) const { return Point(x / k, y / k); }
  double rad(Point a, Point b) {
    Point p = *this;
    return fabs(atan2(fabs((a - p) ^ (b - p)), (a - p) * (b - p)));
  }
  Point trunc(double r) {
    double l = len();
    if (!sgn(l)) return *this;
    r /= l;
    return Point(x * r, y * r);
  }
  Point rotleft() { return Point(-y, x); }
  Point rotright() { return Point(y, -x); }
  Point rotate(Point p, double angle) {
    Point v = (*this) - p;
    double c = cos(angle), s = sin(angle);
    return Point(p.x + v.x * c - v.y * s, p.y + v.x * s + v.y * c);
  }
};
struct Line {
  Point s, e;
  Line() {}
  Line(Point _s, Point _e) {
    s = _s;
    e = _e;
  }
  bool operator==(Line v) { return (s == v.s) && (e == v.e); }
  Line(Point p, double angle) {
    s = p;
    if (sgn(angle - pi / 2) == 0) {
      e = (s + Point(0, 1));
    } else {
      e = (s + Point(1, tan(angle)));
    }
  }
  Line(double a, double b, double c) {
    if (sgn(a) == 0) {
      s = Point(0, -c / b);
      e = Point(1, -c / b);
    } else if (sgn(b) == 0) {
      s = Point(-c / a, 0);
      e = Point(-c / a, 1);
    } else {
      s = Point(0, -c / b);
      e = Point(1, (-c - a) / b);
    }
  }
  void input() {
    s.input();
    e.input();
  }
  void adjust() {
    if (e < s) swap(s, e);
  }
  double length() { return s.distance(e); }
  double angle() {
    double k = atan2(e.y - s.y, e.x - s.x);
    if (sgn(k) < 0) k += pi;
    if (sgn(k - pi) == 0) k -= pi;
    return k;
  }
  int relation(Point p) {
    int c = sgn((p - s) ^ (e - s));
    if (c < 0)
      return 1;
    else if (c > 0)
      return 2;
    else
      return 3;
  }
  bool pointonseg(Point p) {
    return sgn((p - s) ^ (e - s)) == 0 && sgn((p - s) * (p - e)) <= 0;
  }
  bool parallel(Line v) { return sgn((e - s) ^ (v.e - v.s)) == 0; }
  int segcrossseg(Line v) {
    int d1 = sgn((e - s) ^ (v.s - s));
    int d2 = sgn((e - s) ^ (v.e - s));
    int d3 = sgn((v.e - v.s) ^ (s - v.s));
    int d4 = sgn((v.e - v.s) ^ (e - v.s));
    if ((d1 ^ d2) == -2 && (d3 ^ d4) == -2) return 2;
    return (d1 == 0 && sgn((v.s - s) * (v.s - e)) <= 0) ||
           (d2 == 0 && sgn((v.e - s) * (v.e - e)) <= 0) ||
           (d3 == 0 && sgn((s - v.s) * (s - v.e)) <= 0) ||
           (d4 == 0 && sgn((e - v.s) * (e - v.e)) <= 0);
  }
  int linecrossseg(Line v) {
    int d1 = sgn((e - s) ^ (v.s - s));
    int d2 = sgn((e - s) ^ (v.e - s));
    if ((d1 ^ d2) == -2) return 2;
    return (d1 == 0 || d2 == 0);
  }
  int linecrossline(Line v) {
    if ((*this).parallel(v)) return v.relation(s) == 3;
    return 2;
  }
  Point crosspoint(Line v) {
    double a1 = (v.e - v.s) ^ (s - v.s);
    double a2 = (v.e - v.s) ^ (e - v.s);
    return Point((s.x * a2 - e.x * a1) / (a2 - a1),
                 (s.y * a2 - e.y * a1) / (a2 - a1));
  }
  double dispointtoline(Point p) { return fabs((p - s) ^ (e - s)) / length(); }
  double dispointtoseg(Point p) {
    if (sgn((p - s) * (e - s)) < 0 || sgn((p - e) * (s - e)) < 0)
      return min(p.distance(s), p.distance(e));
    return dispointtoline(p);
  }
  double dissegtoseg(Line v) {
    return min(min(dispointtoseg(v.s), dispointtoseg(v.e)),
               min(v.dispointtoseg(s), v.dispointtoseg(e)));
  }
  Point lineprog(Point p) {
    return s + (((e - s) * ((e - s) * (p - s))) / ((e - s).len2()));
  }
  Point symmetrypoint(Point p) {
    Point q = lineprog(p);
    return Point(2 * q.x - p.x, 2 * q.y - p.y);
  }
};
int main() {
  long long ax, ay, bx, by, cx, cy;
  cin >> ax >> ay >> bx >> by >> cx >> cy;
  if ((bx - ax) * (bx - ax) + (by - ay) * (by - ay) !=
          (bx - cx) * (bx - cx) + (by - cy) * (by - cy) ||
      (by - ay) * (bx - cx) == (by - cy) * (bx - ax))
    cout << "NO" << endl;
  else
    cout << "YES" << endl;
  return 0;
}