#include <bits/stdc++.h>
int main(void) {
  unsigned int const max_skill_level = 100;
  unsigned int number_of_boys;
  unsigned int number_of_girls;
  unsigned int number_of_pairs = 0;
  std::vector<unsigned int> number_of_boys_with_each_skill_level(
      max_skill_level + 1, 0);
  std::vector<unsigned int> number_of_girls_with_each_skill_level(
      max_skill_level + 1, 0);
  std::ios_base::sync_with_stdio(false);
  std::cin >> number_of_boys;
  for (unsigned int i = 0; i < number_of_boys; ++i) {
    std::size_t skill_level;
    std::cin >> skill_level;
    ++number_of_boys_with_each_skill_level[skill_level];
  }
  std::cin >> number_of_girls;
  for (unsigned int i = 0; i < number_of_girls; ++i) {
    std::size_t skill_level;
    std::cin >> skill_level;
    ++number_of_girls_with_each_skill_level[skill_level];
  }
  for (std::size_t i = 0; i < max_skill_level; ++i) {
    unsigned int number_of_new_pairs;
    number_of_new_pairs = std::min(number_of_boys_with_each_skill_level[i],
                                   number_of_girls_with_each_skill_level[i]);
    number_of_boys_with_each_skill_level[i] -= number_of_new_pairs;
    number_of_girls_with_each_skill_level[i] -= number_of_new_pairs;
    number_of_pairs += number_of_new_pairs;
    number_of_new_pairs =
        std::min(number_of_boys_with_each_skill_level[i],
                 number_of_girls_with_each_skill_level[i + 1]);
    number_of_boys_with_each_skill_level[i] -= number_of_new_pairs;
    number_of_girls_with_each_skill_level[i + 1] -= number_of_new_pairs;
    number_of_pairs += number_of_new_pairs;
    number_of_new_pairs = std::min(number_of_boys_with_each_skill_level[i + 1],
                                   number_of_girls_with_each_skill_level[i]);
    number_of_boys_with_each_skill_level[i + 1] -= number_of_new_pairs;
    number_of_girls_with_each_skill_level[i] -= number_of_new_pairs;
    number_of_pairs += number_of_new_pairs;
  }
  number_of_pairs += std::min(number_of_boys_with_each_skill_level.back(),
                              number_of_girls_with_each_skill_level.back());
  std::cout << number_of_pairs << '\n';
  return 0;
}
