//Justyna Koczar
#include <iostream>
#include <cstdlib>

using namespace std;


bool czy_juz_wpisana(long *tablica,long szukana,long &p);



int main()
{
	long i,j,k,n,m,p;
    long tablica1[140000],tablica2[140000],tablica3[140000];

	cin>>n;
	for(i=0;i<n;i++)
    {
		cin>>tablica1[i];
	}

    cin>>m;
	for(i=0;i<m;i++)
    {
		cin>>tablica2[i];
	}

	p=0;
	for (i=0;i<n;i++)
    {
        for(j=0;j<m;j++)
        {
			if(tablica1[i]==tablica2[j])
            {
				if(czy_juz_wpisana(tablica3,tablica1[i],p))
                {
					tablica3[p]=tablica1[i];
					p++;
				}

			}

        }
    }


    cout<<p<<endl;
    for (i=0;i<p;i++)
    {
		cout<<tablica3[i]<<endl;
    }
	return 0;
}

bool czy_juz_wpisana(long *tablica,long szukana,long &p)
{
		for (int i=0;i<p;i++)
    {
		if(tablica[i]==szukana)
			return false;
	}
	return true;

}