Problem: Given 2 integers u and v, find the shortest array such that [bitwise-xor](https://en.wikipedia.org/wiki/Bitwise_operation#XOR) of its elements is u, and the sum of its elements is v.

Input

The only line contains 2 integers u and v (0 ≤ u,v ≤ 10^{18}).

Output

If there's no array that satisfies the condition, print "-1". Otherwise:

The first line should contain one integer, n, representing the length of the desired array. The next line should contain n positive integers, the array itself. If there are multiple possible answers, print any.

Examples

Input


2 4


Output


2
3 1

Input


1 3


Output


3
1 1 1

Input


8 5


Output


-1

Input


0 0


Output


0

Note

In the first sample, 3⊕ 1 = 2 and 3 + 1 = 4. There is no valid array of smaller length.

Notice that in the fourth sample the array is empty.

Solution (in JAVA):

Solution:
import java.util.*;
import java.lang.*;
import java.io.*;
 
public class d
{
	public static void main (String[] args) throws java.lang.Exception
	{
		MyScanner in = new MyScanner();
        out = new PrintWriter(new BufferedOutputStream(System.out));
		int T=1;
		for(int test=0;test<T;test++){
			long u = in.nextLong();
			long v = in.nextLong();
			if(u==0 && v==0){
			    out.println(0);
			}
			else if((u%2)!=(v%2)){
			    out.println(-1);
			}
			else if(v<u){
			    out.println(-1);
			} else if(u==v){
			    out.println(1);
			    out.println(u);
			} else {
			    long o = (v-u)/2;
			    if((u & o) == 0){
			        out.println(2);
			        out.println((u+o)+" "+o);
			    } else {
			        out.println(3);
			        out.println(u+" "+o+" "+o);
			    }
			}
		}
		out.close();
	}
	public static PrintWriter out;
      
   //-----------MyScanner class for faster input----------
   public static class MyScanner {
      BufferedReader br;
      StringTokenizer st;
 
      public MyScanner() {
         br = new BufferedReader(new InputStreamReader(System.in));
      }
 
      String next() {
          while (st == null || !st.hasMoreElements()) {
              try {
                  st = new StringTokenizer(br.readLine());
              } catch (IOException e) {
                  e.printStackTrace();
              }
          }
          return st.nextToken();
      }
 
      int nextInt() {
          return Integer.parseInt(next());
      }
 
      long nextLong() {
          return Long.parseLong(next());
      }
 
      double nextDouble() {
          return Double.parseDouble(next());
      }
 
      String nextLine(){
          String str = "";
	  try {
	     str = br.readLine();
	  } catch (IOException e) {
	     e.printStackTrace();
	  }
	  return str;
      }
 
   }
}