#include <fstream>
#include <algorithm>
#define Vmax 50009
using namespace std;
ifstream fin("economie.in");
ofstream fout("economie.out");
int n, f, nr, N[1009], Sol[1009];
bool V[Vmax + 9];


int main()
{
    fin >> n;
    for (int k = 1; k <= n; k++)
        fin >> N[k];

    sort(N+1, N+1+n);

    V[0] = 1;
    for (int k = 1; k <= n; k++)
    {
        if(!V[N[k]])
        {
            Sol[++nr] = N[k];
            V[N[k]] = 1;
            for (int i = 0; i <= Vmax - N[k]; i += 1)
            {
                if(V[i]) V[i + N[k]] = 1;
            }
        }
    }

    fout << nr << '\n';
    for (int i = 1; i <= nr; i += 1)
    {
        fout << Sol[i] << '\n';
    }
    fout.close();
    return 0;
}