#include <iostream>
#include <fstream>
#include <algorithm>

using namespace std;

ifstream fin("economie.in");
ofstream fout("economie.out");

int v[1000],n,i,k=1;

void suma()
{
    int Sf=v[0],Sp=v[0],sigur=1;
    for(i=1;i<n;i++)
    {
        Sp+=v[i];
        sigur++;
        if(v[i]%Sf!=0)
        {
            Sf=Sp;
            k=sigur;
        }
    }
}
int main()
{
    fin>>n;
    for(i=0;i<n;i++)
        fin>>v[i];
    sort(v,v+n);
    if(v[0]==1)
        cout<<1<<endl<<1;
    else
    {
        suma();
        cout<<k<<endl;
        for(i=0;i<k;i++)
            cout<<v[i]<<endl;
    }


    return 0;
}