#include <iostream>
#include <fstream>
#include <algorithm>
using namespace std;
ifstream fin("economie.in");
ofstream fout("economie.out");
int n,i,j,nr,S[50001],V[1001],sol[1001];
int main()
{fin>>n;
for(i=1;i<=n;i++)
    fin>>V[i];
sort(V+1,V+n+1);
S[0]=1;
nr=0;
for(i=1;i<=n;i++){
    if(S[V[i]]!=1)
       sol[++nr]=V[i];
    for(j=0;j<=V[n]-V[i];j++)
        if(S[j]==1)
           S[j+V[i]]=1;

}
fout<<nr<<"\n";
for(i=1;i<=nr;i++)
    fout<<sol[i]<<"\n";







    return 0;
}