#include<stdio.h>
long int n,i,j,k,cit,l3,v1[50001],v2[50001],v3[50001];
int main()
{
	FILE *f,*g;f=fopen("economie.in","r");g=fopen("economie.out","w");
	fscanf(f,"%ld",&n);
	for(i=1;i<=n;i++){fscanf(f,"%ld",&j);v1[j]=1;}
	for(i=1;i<=50000;i++)
	if(v1[i])
	 if(!v2[i])
	  { v2[i]=1;l3++;v3[l3]=i;
	    for(j=i;j<=50000;j++)
	     if(v2[j])
	      for(k=j;k<=50000;k=k+i) v2[k]=1;
	  }
	 fprintf(g,"%ld\n",l3);
	 for(i=1;i<=l3;i++)
	  fprintf(g,"%ld\n",v3[i]);
	 fcloseall();
	 return 0;
}