#include <bits/stdc++.h>

using namespace std;

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

const int ELMAX = 50007;

int main()
{
    int n;
    fin >> n;

    vector<int> v(n + 1);
    vector<bool> frecv(ELMAX);

    int maxim = 0;

    for (int i = 1; i <= n; i++)
    {
        fin >> v[i];
        frecv[v[i]] = true;
        maxim = max(maxim, v[i]);
    }

    sort(v.begin(), v.end());

    int ans = 0;
    vector<bool> esol(n + 1), dp(ELMAX);
    dp[0] = true;

    for (int i = 1; i <= n; i++)
    {
        for (int j = v[i]; j <= maxim; j++)
        {
            if (dp[j - v[i]])
            {
                if (!dp[j] && frecv[j] && !esol[i])
                {
                    ans++;
                    esol[i] = true;
                }
                dp[j] = true;
            }
        }
    }

    fout << ans << '\n';
    for (int i = 1; i <= n; i++)
    {
        if (esol[i])
            fout << v[i] << '\n';
    }

    return 0;
}