#include<stdio.h>
#include<algorithm>
using namespace std;

#define maxim(a,b) (a>b ? a : b)

int sol[1005],v[1005];
int vmax,f[50006],n,nr;

int main ()
{
    int i,j;
    freopen("economie.in","r",stdin);
    freopen("economie.out","w",stdout);
    scanf("%d",&n);
    for(i=1;i<=n;i++)
    {
        scanf("%d",&v[i]);
        vmax=maxim(vmax,v[i]);
    }
    sort(v+1,v+n+1);
    f[0]=1;
    for(i=1;i<=n;i++)
        if(!f[v[i]])
        {
            sol[++nr]=v[i];
            for(j=0;j<=vmax-v[i];j++)
                if(f[j])
                    f[j+v[i]]=1;
        }
    printf("%d\n",nr);
    for(i=1;i<=nr;i++)
        printf("%d\n",sol[i]);
    return 0;
}