Nw = gets.to_i
W = gets.split.map(&:to_i)
Nb = gets.to_i
B = gets.split.map(&:to_i)
A = [B, W]
def f(h, i)
  x = A[i].select {|a| a < h}.max
  if x
    f(x, 1 - i) + 1
  else
    0
  end
end
ans = [f(Float::INFINITY, 0), f(Float::INFINITY, 1)].max
puts ans