#include "bits/stdc++.h"
//speed coding

#define mp make_pair
#define cve(tpy) for (auto i : tpy) {for(auto j : i){cout << j << " ";  }cout << "\n";} ;
#define f first
#define s second
#define loop(i, x, n) for (int i = x; i < n; i++)
#define joop(x, n) for (ll j = x; j < n; j++)
#define lp(n) for (ll i = 0; i < n; i++)
#define err cout << "ERROR" << endl;
#define all(x) x.begin(), x.end()
#define pb push_back
#define sz(x) x.size()
#define rndm rng()

// types
#define pii pair<int, int>
#define pll pair<ll, ll>
#define vvi vector<vector<int>>
#define vvll vector<vector<ll>>
typedef long long ll;
typedef long double ld;

// types of data
#define inf 1000000000
#define infll 1000000000000000000
#define INF ll(1e18)

#define md 998244353
#define mod 1000000009
//#define K 239017

#define DEBUG 1
using namespace std;
mt19937_64 rng(113113);
uniform_int_distribution<ll> drist;


void solve() {
    int a, b;
    cin >> a >> b;
    vector<pii > p(b + 1, mp(inf, -1));
    if (a > b) {
        cout << "-1\n";
        return;
    }
    p[a] = mp(0, -1);
    loop(i, a, b + 1) {
        if (i * 2 <= b) {
            int x = min(p[i].f + 1, p[2 * i].f);
            if (x == p[i].f + 1) {
                p[2 * i] = mp(p[i].f + 1, 0);

            }
        }
        if (i * 10 + 1 <= b) {
            int x = min(p[i].f + 1, p[i * 10 + 1].f);
            if (x == p[i].f + 1) {
                p[i * 10 + 1] = mp(p[i].f + 1, 1);

            }
        }
    }
    for (auto i: p) {
//        cout << i << " ";
    }
    if(p[b].f != inf){
        cout << p[b].f << "\n";
        vector<int> ans;
        while(b != a){
            if(p[b].s == 0 ){
                ans.pb(0);
                b/=2;
            }else if(p[b].s == 1 ){
                ans.pb(1);
                b= (b-1)/10;
            }
        }
        reverse(all(ans));
        for(auto i : ans){
            cout << i << " ";
        }

    }
}


int main() {
    ios::sync_with_stdio(0);
    cin.tie(0);
#ifdef DEBUG
    freopen("text.txt", "r", stdin);
#endif
    int t = 1;
//    cin >> t;
    loop(i, 0, t) {
        solve();

    }

    return 0;
}