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

#define rep(i,n) for(int i=0;i<(int)(n);i++)
#define ALL(v) v.begin(),v.end()
typedef long long ll;
template <class T> using V=vector<T>;
template <class T> using VV=V<V<T>>;
 
int main(){
  ios::sync_with_stdio(false);
  std::cin.tie(nullptr);
  
  ll n,x,y;
  cin>>n>>x>>y;
  if(x==y){
    cout<<0<<endl;
    return 0;
  }
  if(y%2==0){
    cout<<-1<<endl;
    return 0;
  }
  V<int> A;
  for(int i=n-1;i>=0;i--){
    if(y&(1ll<<i)) A.push_back(i);
  }
  int a=A.size();
  V<int> B(a);
  rep(i,a-1) B[i]=A[i]-A[i+1];
  V<int> ANS;
  ANS.push_back(n);
  rep(i,a-1) ANS.push_back(B[i]);
  int k=ANS.size();
  cout<<k<<endl;
  rep(i,k){
    if(i) cout<<" ";
    cout<<ANS[i];
  }
  
    
  return 0;
}