BAEKJOON_13913

import java.io.*;
import java.sql.Array;
import java.util.*;
public class Main {
    static int MAX=100001;
    static int N;
    static int K;
    static BufferedWriter bw;
    static BufferedReader br;

    public static void Print(int[] from,int n,int m) throws IOException{
        if(n!=m){
            Print(from,n,from[m]); 
        }
        bw.write(m + " ");
    }
    public static void main(String[] args) throws IOException {
        br = new BufferedReader(new InputStreamReader(System.in));
        bw = new BufferedWriter(new OutputStreamWriter(System.out));

        StringTokenizer st = new StringTokenizer(br.readLine());
        Queue<Integer> q = new LinkedList<>();
        N = Integer.parseInt(st.nextToken());
        K = Integer.parseInt(st.nextToken());

        int[] from = new int[100001];
        boolean[] v = new boolean[1000001];
        int[] dist = new int[100001];

        dist[N] = 0;
        v[N]=true;
        q.add(N);

        while (!q.isEmpty()) {
            int now = q.poll();     //처음에 5를 꺼낸다.

            if(now -1 >=0){
                if (!v[now - 1]) {
                    v[now-1]=true;
                    q.add(now - 1);
                    dist[now-1]=dist[now]+1;
                    from[now-1] = now;
                }
            }

            if (now + 1 < MAX) {
                if (!v[now + 1]) {
                    v[now+1]=true;
                    q.add(now + 1);
                    dist[now + 1] = dist[now] + 1;
                    from[now+1] = now;
                }
            }

            if (2 * now < MAX) {
                if (!v[2 * now]) {
                    v[2 * now] = true;
                    q.add(2 * now);
                    dist[2 * now] = dist[now] + 1;
                    from[2*now] = now;
                }
            }
        }

        bw.write(String.valueOf(dist[K]));
        bw.newLine();
        Print(from,N,K);
        bw.flush();
        bw.close();
    }

}