#include <fstream>
#include <vector>


using namespace std;

int *a;
int *b;
vector<int>c;
short m1, m2;
short i, j;



int main()
{
	ifstream in("cmlsc.in");
	ofstream out("cmlsc.out");
	in >> m1;
	a = new int[m1];
	in >> m2;
	b = new int[m2];
	for (i = 0; i < m1; i++)
		in >> a[i];
	for (i = 0; i < m2; i++)
		in >> b[i];

	for (i = 0; i < m1; i++)
	{
		for (j = 0; j < m2; j++)
		{
			if (a[i] == b[j])
			{
				c.push_back(a[i]);
				break;
			}
		}
	}
    out << c.size() << "\n";
	for (i = 0; i < c.size(); i++)
		out << c[i] << " ";

	return 0;
}