#include <bits/stdc++.h>
#include <atcoder/all>


using namespace std;
using namespace atcoder;
#define rep(i,m,n,k) for (int i = (int)(m); i < (int)(n); i += (int)(k))
#define rrep(i,m,n,k) for (int i = (int)(m); i > (int)(n); i += (int)(k))
#define ll long long
#define list(T,A,N) vector<T> A(N);for(int i=0;i<(int)(N);i++){cin >> A[i];}

int main(){
    
    ll D;
    cin >> D;
    list(ll,A,D+1);
    if (D==0){
        cout << 0 << endl;
        cout << A[0] << endl;
        return 0;
    }
    ll m,q,a;
    rrep(i,D,2,-1){
        m = i/3;
        q = i%3;
        a = A[i];
        A[m+q] += a;
        A[i] = 0;
    }
    if (A[2]!=0){
        cout << 2 << endl;
        cout << A[0] << ' ' << A[1] << ' ' << A[2] << endl;
        return 0;
    }
    if (A[1]!=0){
        cout << 1 << endl;
        cout << A[0] << ' ' << A[1] << endl;
        return 0;
    }
    cout << 0 << endl;
    cout << A[0]  << endl;
    return 0;

}