#include <iostream>
#include <fstream>
#include <vector>
#include <algorithm>
#define nmax 1005
#define valmax 50005
using namespace std;

int n, v[nmax];
bool can[valmax];
vector <int> sol;

int main() {
	ifstream f("economie.in");
	ofstream g("economie.out");

	f>>n;
	for(int i=1; i<=n; i++) f>>v[i];
	sort(v+1, v+n+1);

	can[0] = true;
	for(int i=1; i<=n; i++)
		if(!can[v[i]]) { //no can dosville, baby doll
			sol.push_back(v[i]);
			for(int j=v[i]; j<valmax; j++)
				if(can[j - v[i]]) can[j] = true;
		}

	g<<sol.size()<<"\n";
	for(int i=0; i<int(sol.size()); i++) g<<sol[i]<<"\n";

	return 0;
}