#include <fstream>
#include <algorithm>
using namespace std;
int n, i, v[1001], sol[1001], a[50001], j, k;

int main () {
    ifstream fin ("economie.in");
    ofstream fout ("economie.out");
    fin>>n;
    a[0]=1;
    for (i=1;i<=n;i++) {
        fin>>v[i];
    }
    sort(v+1, v+n+1);

    for (i=1;i<=n;i++) {
        if (a[v[i]]==0) {
            for (j=0;j<=v[n]-v[i];j++) {
                if (a[j]==1)
                    a[j+v[i]]=1;
            }
            sol[++k]=v[i];
        }
    }

    fout<<k<<"\n";
    for(i=1;i<=k;i++)
        fout<<sol[i]<<"\n";

    return 0;
}