#include <bits/stdc++.h>


using namespace std;

main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    vector<long long> st(62);
    st[0] = 1;
    for(int i = 1; i < 62; i++) st[i] = st[i-1]*2;


    long long len,k;
    cin>>len>>k;

    long long mx = st[len]-1;
    vector<long long> ans;
    ans.push_back(mx);
    k--;

    long long del = 0;
    long long ptr = 0;
    while(k>0){
        long long deleted = 0;
        long long addition = 0;
        while(k>=st[addition]){
            k-=st[addition];
            addition++;

            ans.push_back(mx-del-st[ptr]);
            deleted+=st[ptr];
            ptr++;
        }
        del+=deleted;
    }
    cout<<ans.size()<<"\n";
    for(auto t:ans) cout<<t<<" ";
}