#include <bits/stdc++.h>
using namespace std;

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

    long long N,X,Y; cin >> N >> X >> Y;
    if(X == Y){cout << 0 << endl; return 0;}
    if(Y%2 == 0){cout << "-1" << endl; return 0;}
    
    int zero = 0;
    vector<int> need;
    for(int i=N-1; i>=0; i--){
        if((1LL<<i)&Y) need.push_back(zero),zero = 0;
        else zero++;
    }
    cout << need.size()+60 << endl;
    for(int i=0; i<60; i++) cout << 1 << " ";
    for(auto &n : need) cout << n+1 << " "; cout << "\n";
}