#include <fstream>
#include <algorithm>

using namespace std;

ifstream fin("economie.in");
ofstream fout("economie.out");

const int nmax= 1000;
const int smax= 50000;

int v[nmax+1], sol[nmax+1];
bool sum[smax+1];

int main(  ) {
    int n;
    fin>>n;
    for ( int i= 1; i<=n; ++i ) {
        fin>>v[i];
    }
    sort(v+1, v+n+1);

    int k= 1;
    sum[0]= 1;
    for ( int i= 1; i<=n; ++i ) {
        if ( sum[v[i]]==1 ) {
            continue;
        }

        sol[k]= v[i];
        ++k;
        for ( int j= 0; j<=smax-v[i]; ++j ) {
            if ( sum[j]==1 ) {
                sum[j+v[i]]= 1;
            }
        }
    }
    
    fout<<k-1<<"\n";
    for ( int i= 1; i<k; ++i ) {
        fout<<sol[i]<<"\n";
    }

    return 0;
}