#include<cstdio>
#include<algorithm>
using namespace std;
int a[1001],r[50001],s[50001],i,j,k,n,l,c[1001],w[50001];
int main()
{freopen("economie.in","r",stdin),freopen("economie.out","w",stdout);
scanf("%d",&n);
for(i=1;i<=n;i++)
      scanf("%d",&a[i]);
sort(a+1,a+n+1),s[a[1]]=a[1];
for(i=2;i<=n;i++)
      {for(j=a[1];j<=a[n];j++)
             r[j]=s[j];
      if(r[a[i]]<a[i])
             s[a[i]]=a[i];
      for(j=a[1];j<=a[n]-a[i];j++)
      if(r[j+a[i]]<r[j]+a[i])
             s[j+a[i]]=r[j]+a[i],w[j+a[i]]++;}
for(i=1;i<=n;i++)
if(!w[a[i]])
      c[++k]=a[i];                   
printf("%d\n",k);
for(i=1;i<=k;i++)
      printf("%d\n",c[i]);
return 0;}