#include <stdio.h>
#include <algorithm>
using namespace std;
int main()
{
	freopen("economie.in","r",stdin);
	freopen("economie.out","w",stdout);
	int n,i,r,j,min,cont,m=0,sol=0,suma=0;
	int a[1005],b[1005],c[1005];
	scanf("%d",&n);
	for (i=1; i<=n; i++)
		scanf("%d\n",&a[i]);
	sort(a+1,a+n+1);
	for (i=1; i<=n; i++)
		c[i]=0;
	cont=1;
	b[++m]=a[++m];
	while (sol==0)
	{
	for (i=1; i<=n; i++)
		if (a[i]%b[m]==0)
			c[i]=1;
	for (i=1; i<=n; i++)
		if (c[i]==1)
			sol=1;
		else
		{
			sol=0;
			b[++m]=a[++m];
			break;
		}
	}
	printf("%d\n",m);
	for (i=1; i<=m; i++)
		printf("%d\n",b[i]);
return 0;
}