#include <iostream>

using namespace std;

int main() {

  freopen("input.txt", "r", stdin);
  freopen("output.txt", "w", stdout);

  int a[5];
  int b[5];
  int c[10];

  int na, nb;
  cin >> na;
  for (int i = 0; i < na; i++)
    cin >> a[i];
  cin >> nb;
  for (int i = 0; i < nb; i++)
    cin >> b[i];
  int count = 0;

  for (int i = 0; i < na; i++)
    for (int j = 0; j < nb; j++)
      if (a[i] == b[j]) {
        c[count] = a[i];
        count++;
        b[j] = -100000000;
      }

  cout << count << '\n';
  for (int i = 0; i < count; i++)
    cout << c[i] << ' ';
  cout << '\n';

  return 0;
}