#include <fstream>
#include <algorithm>
using namespace std;
int n,i,j,t,S[50001],sol[1001],v[1001],ok,k;
int main()
{
    ifstream cin("economie.in");
    ofstream cout("economie.out");
    cin>>n;
    for(i=1;i<=n;i++)
        cin>>v[i];
    sort(v+1,v+n+1);
    k=0;
    S[0]=1;
    for(i=1;i<=n;i++){
            if(S[v[i]]==0){
                sol[++k]=v[i];
                S[v[i]]=1;
            }
        for(j=0;j<=v[n]-v[i];j++)
            if(S[j]==1){
                S[j+v[i]]=1;
        }
    }
    cout<<k<<'\n';
    for(i=1;i<=k;i++)
        cout<<sol[k]<<'\n';


    return 0;
}