#define _USE_MATH_DEFINES
#include  <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
#include <string>
#include<math.h>
#include<iomanip>
#include<stdio.h>
#include <stdlib.h>
#include<stdio.h>
#include <queue>
#include<map>
#include <fstream>
#include <sstream>
#include<set>
#include<stack>
#include<time.h>
#include <sys/types.h>
#include <tuple>
#include <numeric>
#include <iterator>
#include <atcoder/all>
#include <bits/stdc++.h>

#define rep(i,n) for (int i = 0; i < (n); ++i)
using namespace atcoder;
using namespace std;
typedef long long int ll;
typedef modint998244353 mint;




ll gcd(ll a, ll b) {
    if (a < b)swap(a, b);
    if (b == 0)return a;

    return gcd(b, a % b);
}
int lcm(int a, int b) {
    return a * b / gcd(a, b);
}

/*
解説動画参考
解説ブログ参考

*/



int main()
{

    int Q;
    Q = 1;
    //cin >> Q;   
    
    
    while (Q--) {
        int d;
        cin >> d;
        vector<int>a(d+1);
        for (int i = 0; i <= d; i++)cin >> a[i];
       
        
        for (int i = d; i >2; i--) {
            int t = a[i];
            
            a[i - 2] += t;
            

        }
        for (int i = 2; i >= 0; i--) {
            if (a[i]) {
                cout << i << endl;
                for (int j = 0; j <=i; j++)cout << a[j] << " ";
                return 0;
            }
        }
        cout << 0 << endl;
        cout << a[0]<<endl;
      
    }
    return 0;
}