#include #include using namespace std; #define rep(i, n) for (int i = 0; i < (int)(n); i++) #define all(x) (x).begin(), (x).end() #define ll long long #define ld long double #define INF 1000000000000000000 typedef pair pll; typedef pair pint; template struct SegTree { using Func = function; const Func F; const Monoid UNITY; int SIZE_R; vector dat; SegTree(int n, const Func f, const Monoid &unity) : F(f), UNITY(unity) { init(n); } void init(int n) { SIZE_R = 1; while (SIZE_R < n) SIZE_R *= 2; dat.assign(SIZE_R * 2, UNITY); } /* set, a is 0-indexed */ void set(int a, const Monoid &v) { dat[a + SIZE_R] = v; } void build() { for (int k = SIZE_R - 1; k > 0; --k) dat[k] = F(dat[k * 2], dat[k * 2 + 1]); } /* update a, a is 0-indexed */ void update(int a, const Monoid &v) { int k = a + SIZE_R; dat[k] = v; while (k >>= 1) dat[k] = F(dat[k * 2], dat[k * 2 + 1]); } /* get [a, b), a and b are 0-indexed */ Monoid get(int a, int b) { Monoid vleft = UNITY, vright = UNITY; for (int left = a + SIZE_R, right = b + SIZE_R; left < right; left >>= 1, right >>= 1) { if (left & 1) vleft = F(vleft, dat[left++]); if (right & 1) vright = F(dat[--right], vright); } return F(vleft, vright); } inline Monoid operator[](int a) { return dat[a + SIZE_R]; } /* debug */ void print() { for (int i = 0; i < SIZE_R; ++i) { cout << (*this)[i]; if (i != SIZE_R - 1) cout << ","; } cout << endl; } }; int main() { cin.tie(0); ios::sync_with_stdio(false); int N; cin >> N; vector a(N), b(N), c(N); rep(i, N) { cin >> a[i]; a[i]--; } rep(i, N) { cin >> b[i]; b[i]--; } rep(i, N) { c[a[i]] = i; } function f = [](ll a, ll b) { return a + b; }; SegTree tree(N + 5, f, 0); ll ans = 0; rep(i, N) { int ind = c[b[i]]; ans += tree.get(ind, N); tree.update(ind, 1); } cout << ans << endl; }