#define _USE_MATH_DEFINES
#include<iostream>
#include<vector>
#include<algorithm>
#include<cmath>
#include<string>
#include<iomanip>
#include<numeric>
#include<queue>
#include<deque>
#include<stack>
#include<set>
#include<map>
#include<random>
#include<bitset>
#include<cassert>
#include<complex>
#include<fstream>
#include<cstdlib>
#include<functional>
#include<array>
using namespace std;
typedef long long ll;
const int mod=998244353;
const int dx[]={1,0,0,-1},dy[]={0,1,-1,0};
int main(){
	int d,a[10001],dd=2,b[3]={};
	cin>>d;
	for(int i=0;i<=d;i++)
		cin>>a[i];
	for(int i=d;i>=0;i--){
		int tmp=b[2];
		b[2]=b[1];
		b[1]=b[0];
		b[0]=a[i];
		b[1]+=tmp;
	}
	while(dd>0&&b[dd]==0)
		dd--;
	cout<<dd<<endl;
	for(int i=0;i<=dd;i++)
		cout<<b[i]<<(i==dd?'\n':' ');
}