#include <iostream>
#include<fstream>
#include<algorithm>
#define Vmax 50000

 using namespace std;
ifstream fin("economie.in");
ofstream fout("economie.out");
int M[1001],S[50005],n,sol[1001];
int main()
{
    int i,k=0;
     fin>>n;
    for(i=1;i<=n;i++)
        fin>>M[i];

    sort(M+1,M+n+1);

    S[0]=1;

    for(i=1;i<=n;i++)
    {
    if(S[M[i]]==0)

         sol[++k]=M[i];
int j;
    for(j=0;j+M[i]<=Vmax;j++)
      if(S[j])
        S[j+M[i]]=1;


    }
    fout<<k<<"\n";
     for(i=1;i<=k;i++)
        fout<<sol[i]<<"\n";

return 0;
}