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 JAVA):

Solution:
import java.io.*;
import java.util.*;
import java.util.regex.*;
public class vk18
{
    public static void main(String[]stp) throws Exception
    {
    	Scanner scan=new Scanner(System.in);
    	PrintWriter pw = new PrintWriter(System.out);
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StringTokenizer st=new StringTokenizer(br.readLine());
        long ax=Long.parseLong(st.nextToken()),ay=Long.parseLong(st.nextToken()),bx=Long.parseLong(st.nextToken()),by=Long.parseLong(st.nextToken()),cx=Long.parseLong(st.nextToken()),cy=Long.parseLong(st.nextToken());
        //pw.println(ax+" "+ay+" "+bx+" "+by+" "+cx+" "+cy);
        if(ax-bx == bx-cx && ay-by == by-cy) pw.write("No");
        else 
        {
        	if(   (ax-bx)*(ax-bx)  +  (ay-by)*(ay-by) == (bx-cx)*(bx-cx) + (by-cy)*(by-cy)  ) pw.write("Yes");
        	else pw.write("No");
        }
    	pw.flush();

    }

    
}