#include<fstream>
#include<vector>
#include<algorithm>
using namespace std;
ifstream fin("economie.in");
ofstream fout("economie.out");
int n, v[1005], w[50005];
vector<int> sol;
int main(){
    fin >> n;
    for( int i = 1; i <= n; i++ ){
        fin >> v[i];
    }
    sort( v + 1, v + n + 1 );
    w[0] = 1;
    for( int i = 1; i <= n; i++ ){
        if( w[ v[i] ] == 0 ){
            sol.push_back( v[i] );
            for( int j = 0; j <= v[n]; j++ ){
                if( w[j] == 1 && j + v[i] <= v[n] ){
                    w[ j + v[i] ] = 1;
                }
            }
        }
    }
    fout << sol.size() << "\n";
    for( int i = 0; i < sol.size(); i++ ){
        fout << sol[i] << "\n";
    }
    return 0;
}