from bisect import bisect_right,insort_right
N=int(input())
A=list(map(int, input().split()))
B=list(map(int, input().split()))
dic = {}
for i in range(N):
  dic[B[i]] = i
for i in range(N):
  A[i] = dic[A[i]]
lis = [A[0]]
ans=0
for i in range(1,N):
  idx = bisect_right(lis,A[i])
  ans += i-idx
  insort_right(lis,A[i])
print(ans)