#include<algorithm>
#include<fstream>

using namespace std;
ifstream fin("economie.in");
ofstream fout("economie.out");
int v[1005],z[1005];
int f[50005];
int n,i,j,k,ok,maxi;

int main()
{
    fin>>n;
    for(i=1;i<=n;i++)
    {
        fin>>v[i];
        if(v[i]>maxi)
            maxi=v[i];
    }
    sort(v+1, v+1+n);
    f[0]=1;
    for(i=1;i<=n;i++)
    {
        if(f[v[i]]==0)
        {
            z[++k]=v[i];
            for(j=0;j<=maxi;j++)
            {
                if(f[j]==1&&j+v[i]<=maxi)
                    f[j+v[i]]=1;
            }
        }
    }
    fout<<k<<"\n";
    for(i=1;i<=k;i++)
        fout<<z[i]<<"\n";
    fin.close();
    fout.close();
    return 0;
}