#!/usr/bin/env pypy3

def merge_list(left,right):
    result = list()
    i,j = 0,0
    inv_count = 0
    while i < len(left) and j < len(right):
        if left[i] <= right[j]:
            result.append(left[i])
            i += 1
        else:
            result.append(right[j])
            j += 1
            inv_count += (len(left)-i)
    result += left[i:]
    result += right[j:]
    return result,inv_count


def sort_and_count(array):
    if len(array) <= 1:
        return array, 0
    middle = len(array) // 2
    left,inv_left = sort_and_count(array[:middle])
    right,inv_right = sort_and_count(array[middle:])
    merged, count = merge_list(left,right)
    count += (inv_left + inv_right)
    return merged, count


def count_inversions(arr):
    _, ret = sort_and_count(arr)
    return ret

input()
A = input().split(' ')
A = list(map(int, A))
B = input().split(' ')
B = list(map(int, B))

translation = dict()
for i, b in enumerate(B):
    translation[b] = i
A = list(map(translation.get, A))

print(count_inversions(A))