#include<stdio.h>
#include<algorithm>

using namespace std;
char ok[50001];
int b[1001];
long n,i,j;
int Maxim;
long ans,sol[1001];
int main(){
	
    freopen("economie.in","r",stdin);
    freopen("economie.out","w",stdout);
    
    scanf("%d",&n);
    for (i=1;i<=n;i++){
		
        scanf("%d",&b[i]);
        if (b[i]>Maxim)
           Maxim=b[i];
    }
	
    sort(b+1,b+n+1);
    
    for (i=1;i<=n;i++){
        if (ok[b[i]]==0){
                    ++ans;
                    sol[ans]=b[i];
			for (j=b[i];j<=Maxim;j+=b[i])
				ok[j]=1;
			for (j=1;j<=Maxim;++j)
				if ( ok[j]==1 && j+b[i]<=Maxim)
						ok[j+b[i]]=1;
        }
    }
	
    printf("%ld\n",ans);
	
    for (i=1;i<=ans;i++)
        printf("%ld\n",sol[i]);
    return 0;
}