#include <stdio.h>
FILE *f= fopen("economie.in","r");
FILE *g= fopen("economie.out","w");
unsigned char ok[50040];
unsigned ax,n,a[1040],max,i,j,min[1040],k=0;
int main()
 {
 fscanf(f,"%d",&n);
 for(i=1;i<=n;i++)
  {
  fscanf(f,"%d",&a[i]);
  if(a[i]>max||i==1)
   max=a[i];
  }
// fprintf(f,"\n");
 for(i=1;i<n;i++)
  for(j=i+1;j<=n;j++)
   if(a[i]>a[j])
    {
    ax=a[i];
    a[i]=a[j];
    a[j]=ax;
    }
 ok[0]=1;
 for(i=1;i<=n;i++)
  {
  if(ok[a[i]]==0)
   min[++k]=a[i];
  for(j=0;j<=max;j++)
   if(ok[j]==1&&j+a[i]<=max)
    ok[j+a[i]]=1;
  }
 fprintf(g,"%d\n",k);  
 for(i=1;i<=k;i++)  
  fprintf(g,"%d\n",min[i]);  
 return 0;  
}