#include <bits/stdc++.h>

using namespace std;

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

const int N_MAX = 1005, VAL_MAX = 50005;

int n, v[N_MAX], w[N_MAX], m, ciur[VAL_MAX];

int main() {
    fin >> n;
    for (int i = 1; i <= n; i++)
        fin >> v[i];
    sort (v + 1, v + 1 + n);
    ciur[0] = 1;
    for (int i = 1; i <= n; i++) {
        if (ciur[v[i]] == 0) {

            w[++m] = v[i];
            for (int j = 0; j <= VAL_MAX - v[i]; j++) {
                if (ciur[j] == 1)
                    ciur[v[i] + j] = 1;
            }
        }
    }
    fout << m << "\n";
    for (int i = 1; i <= m; i++)
        fout << w[i] << "\n";
    return 0;
}