#include <fstream>
#include <algorithm>
using namespace std;

ifstream fin("economie.in");
ofstream fout("economie.out");

int n,v[1001],i,j,sol[1001],cnt,d[50001];

int main(){
    fin>>n;
    for(i=1;i<=n;i++)
        fin>>v[i];
    sort(v+1,v+n+1);
    d[0]=1;
    for(i=1;i<=n;i++){
        if(d[v[i]]==0){
            cnt++;
            sol[cnt]=v[i];
            for(j=0;j+v[i]<=v[n];j++){
                if(d[j]==1 && j+v[i]<=v[n])
                    d[j+v[i]]=1;
            }
        }
    }
    fout<<cnt<<"\n";
    for(i=1;i<=cnt;i++)
        fout<<sol[i]<<"\n";

    return 0;
}