#include <fstream>
#include <algorithm>
using namespace std;
int n,v[1000],s[1000],si;
bool val[100001];
ifstream fin("economie.in");
ofstream fout("economie.out");
int main()
{
	int i,j;
	fin>>n;
	for(i=0;i<n;++i)
		fin>>v[i];
	sort(v,v+n);
	val[0]=1;
	for(i=0;i<n;++i)
		if(!val[v[i]])
		{
			s[si++]=v[i];
			for(j=0;j<=v[n-1]-v[i];++j)
				if(val[j])
					val[j+v[i]]=1;
		}
	fout<<si<<"\n";
	for(i=0;i<si;++i)
		fout<<s[i]<<" ";
	return 0;
}