#include <bits/stdc++.h>
using namespace std;
ifstream f("economie.in");
ofstream g("economie.out");
const int VMAX=50005;
int n;
vector<int>ans,v;
bitset<VMAX>makeable;
void read()
{
    f>>n;
    v=vector<int>(n,0);
    for(int i=0; i<n; i++)
        f>>v[i];
}
void solve()
{
    makeable[0]=1;
    sort(v.begin(),v.end());
    for(int i=0; i<v.size(); i++)
    {
        if(makeable[v[i]])
            continue;
        ans.push_back(v[i]);
        for(int j=0; j+v[i]<=VMAX; j++)
            if(makeable[j])
                makeable[j+v[i]]=1;
    }
}
void write()
{
    g<<ans.size()<<"\n";
    for(int i=0; i<ans.size(); i++)
        g<<ans[i]<<"\n";
}
int main()
{
    read();
    solve();
    write();
    return 0;
}