#include <fstream>
#define inf 5000000
#include <cstring>
#include <algorithm>
using namespace std;
ifstream f("economie.in");
ofstream g("economie.out");
int i,j,n,k,v[1001],a[50001],sol[1001];
int main()
{   f>>n;
    for(i=1;i<=n;i++)
        f>>v[i];
    sort(v+1,v+n+1);
    a[0]=1;
    k=0;
    for(i=1;i<=n;i++){
        if(a[v[i]]==0){
            sol[++k]=v[i];
            for(j=0;j<=v[n]-v[i];j++)
                if(a[j]==1)
                    a[j+v[i]]=1;
        }
    }
    g<<k<<'\n';
    for(i=1;i<=k;i++)
        g<<sol[i]<<'\n';
    return 0;
}