#include <bits/stdc++.h>

using namespace std;

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

const int NMAX = 1000, SMAX = 50001;

int V[NMAX + 5], Sol[NMAX + 5], N, ct;

bool S[SMAX + 5];

int main()
{
    fin >> N;

    for(int i = 0; i < N; i++)
        fin >> V[i];

    sort(V, V + N);

    S[0] = true;

    for(int i = 0; i < N; i++)
    {
        if(!S[V[i]]) {
            for(int k = 0; k < SMAX; k++) {
                if(S[k] && k + V[i] < SMAX)
                    S[k + V[i]] = true;
            }
            Sol[ct++] = V[i];
        }
    }

    fout << ct << '\n';

    for(int i = 0; i < ct; i++)
        fout << Sol[i] << '\n';

    fin.close();
    fout.close();

    return 0;
}