#include<cstdio>
#include<vector>


using namespace std;


int main(void)
{
	int d, i, j;
	vector<int> a;

	while(scanf("%d", &d)==1)
	{
		a.resize(d+1);
		for(i=0;i<=d;i++) scanf("%d", &a[i]);

		for(i=d;i>=3;i--)
		{
			a[i-2]+=a[i];
			a[i]=0;
		}

		for(i=2;i>0;i--)
		{
			if(a[i]) break;
		}
		printf("%d\n%d", i, a[0]);
		for(j=1;j<=i;j++) printf(" %d", a[j]);
		printf("\n");
	}

	return 0;
}