io = STDIN
io.gets
aa = io.gets.split(' ').map(&:to_i)
ba = io.gets.split(' ').map(&:to_i)

max = 0
aa.sort.reverse.zip(ba.sort) do |a, b|
  point = a - b
  max += point.positive? ? point : 0
end

count = 0
aa.permutation do |a_seq|
  sum = 0
  a_seq.zip(ba) do |a, b|
    point = a - b
    sum += point if point.positive?
  end
  count += 1 if sum == max
end

puts count