if __name__ == '__main__':
  # 入力
  N = int(input())
  expected_value = list(map(int, input().split(' ')))
  level_of_satisfaction = list(map(int, input().split(' ')))

  # 満足した人数
  number_of_people_satisfied = 0

  for i in range(N):
    if expected_value[i] <= level_of_satisfaction[i]:
      number_of_people_satisfied += 1

  print(number_of_people_satisfied)