class BIT: """一点加算、区間取得クエリをそれぞれO(logN)で答えるデータ構造""" def __init__(self, n): self.size = n self.bit = [0] * (n + 1) def build(self, array): """arrayを初期値とするBinaryIndexTreeを構築する O(N)""" for i in range(self.size): self.bit[i + 1] = array[i] for i in range(1, self.size): if i + (i & -i) > self.size: continue self.bit[i + (i & -i)] += self.bit[i] def _sum(self, i): s = 0 while i > 0: s += self.bit[i] i -= i & -i return s def add(self, i, val): """i番目の要素にvalを加える""" i += 1 while i <= self.size: self.bit[i] += val i += i & -i def get_sum(self, l, r): """区間[l, r)の和を求める""" return self._sum(r) - self._sum(l) n = int(input()) a = list(map(int, input().split())) b = list(map(int, input().split())) mapping = {} for i in range(n): mapping[a[i]] = i c = [0] * n for i in range(n): c[i] = mapping[b[i]] bit = BIT(n) ans = 0 for i in range(n)[::-1]: bit.add(c[i], 1) ans += bit.get_sum(0, c[i]) print(ans)