#include<fstream>
#include<algorithm>
using namespace std;
ifstream fin("economie.in");
ofstream fout("economie.out");
int n,i,j,ok;
int v[1003],w[1003],f[50003];
int main(){
    fin>>n;
    for(i=1;i<=n;i++){
        fin>>v[i];
    }
    sort(v+1,v+n+1);
    f[0]=1;
    for(i=1;i<=n;i++){
        if(f[v[i]]==0){
            w[++ok]=v[i];
            for(j=0;j<=v[n];j++){
                if(f[j]==1&&j+v[i]<=v[n]){
                    f[j+v[i]]=1;
                }
            }
        }
    }
    fout<<ok<<"\n";
    for(i=1;i<=ok;i++){
        fout<<w[i]<<"\n";
    }
    return 0;
}