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

int i,j,n,m,a[1001],uz[50001],nr=0,sol[1001];
bool cmp(int a,int b)
{
    return a<b;
}
int main()
{
    ifstream f("economie.in");
    ofstream g("economie.out");
    f>>n;
    for(i=1;i<=n;++i)
    f>>a[i];
    sort(a+1,a+n+1,cmp);
    m=a[n];
    uz[0]=1;
    for(i=1;i<=n;++i)
    if(!uz[a[i]])
    {
    for(j=1;j<=m;++j)
    if(j>=a[i]&&uz[j-a[i]]==1)
    uz[j]=1;
    sol[++nr]=a[i];
    }
    g<<nr<<"\n";
    for(i=1;i<=nr;++i)
    g<<sol[i]<<"\n";
}