#include <cstdio>
#include <cstdlib>
#include <iostream>
#include <string>
#include <cmath>
#include <algorithm>
#include <vector>
#include <queue>
#include <stack>
#include <map>
#include <set>
#include <cstring>

typedef long long ll;
using namespace std;

#define mod 1000000009
#define INF 10000000
#define LLINF 2000000000000000000LL

#define SIZE 10001

int main(){
    int d,d_,a[SIZE];
    
    scanf("%d",&d);
    
    for(int i=0;i<=d;i++) scanf("%d",&a[i]);
    
    for(int i=d;i>=3;i--){
        a[i-2]+=a[i];
        a[i]=0;
        
    }
    
    for(d_=d;d_>=0;d_--){
        if(a[d_]!=0){
            break;
        }
    }
    
    if(d_==-1) d_=0;
    
    printf("%d\n",d_);
    
    for(int i=0;i<=d_;i++){
        
        printf(i==d_ ?"%d\n":"%d ",a[i]);
        
    }
    
    
    return 0;
}