#include<cstdio>
#include<algorithm>
using namespace std;
int n,i,j,p,q,v[1005];
int w[50005],sol[1005];
int main()
{
    freopen("economie.in","r",stdin);
    freopen("economie.out","w",stdout);
    scanf("%d",&n); w[0]=1;
    for (i=1;i<=n;i++)
    scanf("%d",&v[i]);
    sort(v+1,v+n+1);
    for (i=1;i<=n;i++)
    if (!w[v[i]])
    {
        sol[++sol[0]]=v[i];
        for (j=0;j<=v[n]-v[i];j++) if (w[j])
        w[j+v[i]]=1;
    }
    printf("%d\n",sol[0]);
    for (i=1;i<=sol[0];i++)
    printf("%d\n",sol[i]);
    return 0;
}