#include #define show(x) cerr << #x << " = " << x << endl using namespace std; using ll = long long; using pii = pair; using vi = vector; template ostream& operator<<(ostream& os, const vector& v) { os << "sz=" << v.size() << "\n["; for (const auto& p : v) { os << p << ","; } os << "]\n"; return os; } template ostream& operator<<(ostream& os, const pair& p) { os << "(" << p.first << "," << p.second << ")"; return os; } constexpr ll MOD = 1e9 + 7; template constexpr T INF = numeric_limits::max() / 100; class DisjointSets { public: DisjointSets(const int v) { m_parent.resize(v); m_rank.resize(v); m_size.resize(v); for (int i = 0; i < v; i++) { m_parent[i] = i; m_rank[i] = 0; m_size[i] = 1; } } bool same(const int a, const int b) { return find(a) == find(b); } int find(const int a) { if (m_parent[a] == a) { return a; } else { return m_parent[a] = find(m_parent[a]); } } void unite(const int a_, const int b_) { const int a = find(a_); const int b = find(b_); if (a == b) { return; } if (m_rank[a] > m_rank[b]) { m_parent[b] = a; m_size[a] += m_size[b]; } else { m_parent[a] = b; m_size[b] += m_size[a]; } if (m_rank[a] == m_rank[b]) { m_rank[b]++; } } int getSize(const int a) { return m_size[m_parent[a]]; } private: vector m_parent; vector m_rank; vector m_size; }; int main() { cin.tie(0); ios::sync_with_stdio(false); int N; cin >> N; DisjointSets auf(N); vector A(N); DisjointSets buf(N); vector B(N); for (int i = 0; i < N; i++) { cin >> A[i]; A[i]--; auf.unite(i, A[i]); } for (int i = 0; i < N; i++) { cin >> B[i]; B[i]--; buf.unite(i, B[i]); } using P = pair; map num; for (int i = 0; i < N; i++) { num[make_pair(auf.find(i), buf.find(i))]++; } ll sum = 0; for (const auto& p : num) { const int a = p.first.first; const int b = p.first.second; const ll cnt = lcm((ll)(auf.getSize(a)), (ll)(buf.getSize(b))) - p.second; sum += ((cnt + 1) * cnt / 2) % MOD; sum %= MOD; } cout << sum << endl; return 0; }