_nw = gets.to_i
w = gets.split.map(&:to_i).sort
_nb = gets.to_i
b = gets.split.map(&:to_i).sort
ans = 0

[[w, b], [b.dup, w.dup]].each do |arr|
  i = tmp = 0

  while (l = arr[i].pop)
    arr[i ^= 1].reject! { |e| e >= l }
    tmp += 1
  end

  ans = tmp if ans < tmp
end

puts ans