#include <fstream>
#include <algorithm>
using namespace std;
ifstream fin("economie.in");
ofstream fout("economie.out");
int n,a[1005],v[1005],t;
bool viz[50005];
int main()
{int i,j;
 fin>>n;
 viz[0] = true;
 for(i=1;i<=n;i++) fin>>v[i];
 sort(v+1,v+n+1);
 for(i=1;i<=n;i++)
     if(!viz[v[i]])
 {
     a[++t] = v[i];
     for(j=0;j<=50000-v[i];j++)
         if(viz[j]==true) viz[v[i]+j] = true;
 }
 fout<<t<<"\n";
 for(i=1;i<=t;i++) fout<<a[i]<<"\n";
 fout.close();
 return 0;
}