#include using namespace std; #define FOR(i,a,b) for(int i=(a);i<(b);++i) #define REP(i,n) FOR(i,0,n) #define ALL(v) begin(v),end(v) template inline bool chmax(A & a, const B & b) { if (a < b) { a = b; return true; } return false; } template inline bool chmin(A & a, const B & b) { if (a > b) { a = b; return true; } return false; } using ll = long long; using pii = pair; constexpr ll INF = 1ll<<30; constexpr ll longINF = 1ll<<60; constexpr ll MOD = 1000000007; constexpr bool debug = false; //---------------------------------// /** * @brief https://tkmst201.github.io/Library/DataStructure/BinaryIndexedTree.hpp */ template struct BinaryIndexedTree { using value_type = T; using const_reference = const value_type &; using F = std::function; using size_type = std::size_t; private: size_type n; F f; value_type id_elem; std::vector node; public: BinaryIndexedTree(size_type n, const F & f, const_reference id_elem) : n(n), f(f), id_elem(id_elem), node(n + 1, id_elem) {} size_type size() const noexcept { return n; } void add(size_type i, const_reference x) { assert(i < size()); ++i; for (; i <= size(); i += i & -i) node[i] = f(node[i], x); } value_type sum(size_type i) const { assert(i <= size()); value_type res = id_elem; for (; i > 0; i -= i & -i) res = f(node[i], res); return res; } size_type lower_bound(const_reference x) const { size_type res = 0; size_type s = id_elem, w = 1; while (w < size()) w <<= 1; for (; w > 0; w >>= 1) { if (res + w <= size()) { value_type cur = f(s, node[res + w]); if (cur < x) { res += w; s = cur; } } } return res; } }; int main() { int N; cin >> N; vector A(N), B(N); REP(i, N) scanf("%d", &A[i]); REP(i, N) scanf("%d", &B[i]); sort(ALL(A)); auto compress = [](auto &&v, auto &&cv) -> void { for (auto &&u : v) cv.emplace_back(u); cv.emplace_back(INF); cv.emplace_back(-INF); std::sort(std::begin(cv), std::end(cv)); cv.erase(std::unique(std::begin(cv), std::end(cv)), std::end(cv)); for (auto &&u : v) u = std::lower_bound(std::begin(cv), std::end(cv), u) - std::begin(cv); }; vector cx; compress(B, cx); BinaryIndexedTree bit(cx.size(), [](int x, int y) { return x + y; }, 0); ll ans = 0; REP(i, N) { bit.add(B[i], 1); ans += bit.sum(lower_bound(ALL(cx), A[i]) - cx.begin()); } cout << ans << endl; }