#include <fstream>
#include <algorithm>

using namespace std;

ifstream cin ("economie.in");
ofstream cout ("economie.out");

const int N_MAX = 1000;
const int V_MAX = 50000;

int n, m;

int v[1 + N_MAX];
int Sol[1 + N_MAX];
bool f[1 + V_MAX];

int main()
{
  cin >> n;
  for(int i = 1; i <= n; i++)
    cin >> v[i];
  sort(v + 1, v + n + 1);
  f[0] = 1;
  for(int i = 1; i <= n; i++) {
    if(f[i] == 0) {
      Sol[++m] = v[i];
      for(int j = 0; j <= V_MAX - v[i]; j++)
        if(f[j])
          f[j + v[i]] = 1;
    }
  }
  cout << m << "\n";
  for(int i = 1; i <= m; i++)
    cout << Sol[i] << "\n";
  return 0;
}