#t = int(input())
tt = 1
import random
R = random.randint(1, 1 << 60)
for _ in range(tt):
  n,m = map(int, input().split())
  a = list(map(int, input().split()))
  b = list(map(int, input().split()))
  ans = 0
  for i in a:
    cur = i-1
    if b[cur] == 0:
      ans += 1
    else:
      b[cur] -= 1
  print(ans)