#include<fstream>
#include<algorithm>
using namespace std;
ifstream cin("economie.in");
ofstream cout("economie.out");
int n,i,v[1001],s[50001],a[1001],k;
int main()
{
    cin>>n;
    for(i=1;i<=n;i++)
        cin>>v[i];
    sort(v+1,v+n+1);
    s[0]=1;
    for(i=1;i<=n;i++)
       if(s[v[i]]==0){
             a[++k]=v[i];
         for(int j=0;j<=v[n]-v[i];j++)
               if(s[j]!=0)
                 s[j+v[i]]=1;
       }
    cout<<k<<'\n';
    for(i=1;i<=k;i++)
        cout<<a[i]<<"\n";
    return 0;

}