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.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.StringTokenizer;

public class Main{
	
	String INPUT = "./data/judge/201709/C432B.txt";
	
	public static void main(String[] args) throws IOException {
		new Main().run();
	}
	
	class Point{
		int x;
		int y;
		public Point(int x, int y) {
			this.x = x;
			this.y = y;
		}
	}
	
	public long dist(Point a, Point b) {
		int x1 = a.x;
		int y1 = a.y;
		int x2 = b.x;
		int y2 = b.y;
		long a1 = x2 - x1;
		long b1 = y2 - y1;
		return a1 * a1 + b1 * b1; 
	}
	
	public boolean line(Point a, Point b, Point c) {
		return (long)a.x * b.y - (long)a.y * b.x + (long)b.x * c.y - (long)b.y * c.x + (long)c.x * a.y - (long)c.y * a.x == 0;
	}
	
	void solve() {
		int ax = ni();
		int ay = ni();
		Point a = new Point(ax, ay);
		Point b = new Point(ni(), ni());
		Point c = new Point(ni(), ni());
		
		if (dist(a, b) == dist(b, c) && !line(a, b, c)) out.println("Yes");
		else {
			out.println("No");
		}
	}

	FastScanner in;
	PrintWriter out;
	
	void run() throws IOException {
		boolean oj;
		try {
			oj = ! System.getProperty("user.dir").equals("F:\\java_workspace\\leetcode");
		} catch (Exception e) {
			oj = System.getProperty("ONLINE_JUDGE") != null;
		}
		
		InputStream is = oj ? System.in : new FileInputStream(new File(INPUT));
		in = new FastScanner(is);
		out = new PrintWriter(System.out);
		long s = System.currentTimeMillis();
		solve();
		out.flush();
		if (!oj){
			System.out.println("[" + (System.currentTimeMillis() - s) + "ms]");
		}
	}
	
	public boolean more(){
		return in.hasNext();
	}
	
	public int ni(){
		return in.nextInt();
	}
	
	public long nl(){
		return in.nextLong();
	}
	
	public double nd(){
		return in.nextDouble();
	}
	
	public String ns(){
		return in.nextString();
	}
	
	public char nc(){
		return in.nextChar();
	}
	
	class FastScanner {
		BufferedReader br;
		StringTokenizer st;
		boolean hasNext;

		public FastScanner(InputStream is) throws IOException {
			br = new BufferedReader(new InputStreamReader(is));
			hasNext = true;
		}

		public String nextToken() {
			while (st == null || !st.hasMoreTokens()) {
				try {
					st = new StringTokenizer(br.readLine());
				} catch (Exception e) {
					hasNext = false;
					return "##";
				}
			}
			return st.nextToken();
		}
		
		String next = null;
		public boolean hasNext(){
			next = nextToken();
			return hasNext;
		}

		public int nextInt() {
			if (next == null){
				hasNext();
			}
			String more = next;
			next = null;
			return Integer.parseInt(more);
		}

		public long nextLong() {
			if (next == null){
				hasNext();
			}
			String more = next;
			next = null;
			return Long.parseLong(more);
		}

		public double nextDouble() {
			if (next == null){
				hasNext();
			}
			String more = next;
			next = null;
			return Double.parseDouble(more);
		}
		
		public String nextString(){
			if (next == null){
				hasNext();
			}
			String more = next;
			next = null;
			return more;
		}
		
		public char nextChar(){
			if (next == null){
				hasNext();
			}
			String more = next;
			next = null;
			return more.charAt(0);
		}
	}
}