#include <stdio.h>
int m,i,j,k,n,gas;
int a[1001],b[1001],fol[50001];

int main()
{
	
	freopen("economie.in","r",stdin);
	freopen("economie.out","w",stdout);

	int min=1000,max=0;
	scanf("%d",&n);
	for (i=1; i<=n; i++)
	{
		scanf("%d",&a[i]);
		if (a[i]<min) min=a[i];
		if (a[i]>max) max=a[i];
		fol[a[i]]=1;
	}
	for (i=1; i<=n-1; i++)
		for (j=i+1; j<=n; j++)
		if (a[i]>a[j])
		{
			k=a[i];
			a[i]=a[j];
			a[j]=k;
		}
    m=1;b[m]=a[1];
	for (i=2; i==n; i++)
    {
        gas=0;
        for (j=1; j<=m; j++)
            if (b[j]==a[i])
            {
               gas=1;
               break;               
            }
        if (!gas) { m++;b[m]=a[i];}
    }

    for (i=1; i<=n; i++)
        a[i]=b[i];
    n=m;
    
	for (i=1; i<=n; i++)
	{
		for (j=min; j<=max; j++)
		if (fol[j]==1)
		{
		   int t=1;
		   while (j+t*a[i]<=max)
		   {
				 fol[j+t*a[i]]++;
				 t++;
		   }
		}
	}
	m=0;
	for (i=1; i<=n; i++)
	if (fol[a[i]]==1)
	{
	   m++;
	   b[m]=a[i];
	}
    
    printf("%d\n",m);
    for (i=1; i<=m; i++)
		printf("%d\n",b[i]);

	return 0;
}