#include<bits/stdc++.h>
#define rep(i,s,n) for (int i = (int)(s); i < (int)(n); i++)
#define all(v) begin(v),end(v)
using namespace std;
using ll = long long;
bool chmin(auto &a, auto b){ return a > b ? a = b, 1 : 0; }
bool chmax(auto &a, auto b){ return a < b ? a = b, 1 : 0; }
int main(){
    cin.tie(0)->sync_with_stdio(0);

	ll n,x,y;
	cin >> n >> x >> y;
	if (x==y){
		cout << 0 << '\n';
		return 0;
	}

	if ((y&1) == 0) {
		cout << -1 << '\n';
		return 0;
	}

	deque<ll> bits(n);
	rep(i,0,n){
		bits[n-1-i] = (y>>i&1);
	}

	while(bits.front() == 0) {
		bits.pop_front();
	}
	bits.pop_front();
	
	vector<ll> ls;
	while(!bits.empty()){
		int cnt = 0;
		while(bits.front() == 0) {
			cnt++;
			bits.pop_front();
		}
		cnt++;
		bits.pop_front();
		ls.push_back(cnt);
	}

	
	vector<ll> a;
	a.push_back(n);
	rep(i,0,(int)ls.size()){
		a.push_back(ls[i]);
	}

	cout << (int)a.size() << '\n';
	rep(i,0,(int)a.size()){
		cout << a[i] << ' ';
	}
	cout << '\n';

}