#include <bits/stdc++.h>
const std::string INPUT_FILE = "lcis.in";
const std::string OUTPUT_FILE = "lcis.out";
void ReadFileToVector(std::vector<ssize_t>& sequence) {
  size_t sequence_length;
  std::cin >> sequence_length;
  sequence.assign(sequence_length, 0);
  for (size_t sequence_index = 0; sequence_index < sequence_length;
       ++sequence_index) {
    std::cin >> sequence[sequence_index];
  }
}
int main() {
  std::vector<ssize_t> sequence1;
  std::vector<ssize_t> sequence2;
  ReadFileToVector(sequence1);
  ReadFileToVector(sequence2);
  std::vector<size_t> lcis_length(sequence2.size(), 0);
  std::vector<ssize_t> reference(sequence2.size(), -1);
  for (size_t sequence1_index = 0; sequence1_index < sequence1.size();
       ++sequence1_index) {
    size_t best_lcis = 0;
    ssize_t best_lcis_index = -1;
    for (size_t sequence2_index = 0; sequence2_index < sequence2.size();
         ++sequence2_index) {
      if (sequence1[sequence1_index] == sequence2[sequence2_index] &&
          lcis_length[sequence2_index] < best_lcis + 1) {
        lcis_length[sequence2_index] = best_lcis + 1;
        reference[sequence2_index] = best_lcis_index;
      } else if (sequence1[sequence1_index] > sequence2[sequence2_index] &&
                 lcis_length[sequence2_index] > best_lcis) {
        best_lcis = lcis_length[sequence2_index];
        best_lcis_index = sequence2_index;
      }
    }
  }
  ssize_t lcis_end = 0;
  for (size_t sequence2_index = 1; sequence2_index < sequence2.size();
       ++sequence2_index) {
    if (lcis_length[sequence2_index] > lcis_length[lcis_end]) {
      lcis_end = sequence2_index;
    }
  }
  if (lcis_length[lcis_end] == 0) {
    lcis_end = -1;
  }
  std::vector<ssize_t> lcis;
  size_t lcis_element = lcis_end;
  while (lcis_element != -1) {
    lcis.push_back(sequence2[lcis_element]);
    lcis_element = reference[lcis_element];
  }
  std::cout << lcis.size() << "\n";
  for (ssize_t lcis_index = lcis.size() - 1; lcis_index >= 0; --lcis_index) {
    std::cout << lcis[lcis_index] << " ";
  }
  return 0;
}
