/** * created : 10.11.2024 16:27:18 * author : wzj33300 */ #include using namespace std; #ifdef DEBUG #include #else #define debug(...) 42 #define assert(...) 42 #endif using ll = long long; using u32 = unsigned int; using u64 = unsigned long long; using db = long double; // or double, if TL is tight using str = string; // yay python! // pairs using pi = pair; using pl = pair; using pd = pair; #define fi first #define se second // ^ lol this makes everything look weird but I'll try it template using vc = vector; template using AR = array; using vi = vc; using vb = vc; using vl = vc; using vd = vc; using vs = vc; using vpi = vc; using vpl = vc; using vpd = vc; // vectors // oops size(x), rbegin(x), rend(x) need C++17 #define sz(x) int((x).size()) #define bg(x) begin(x) #define all(x) bg(x), end(x) #define rall(x) x.rbegin(), x.rend() #define sor(x) sort(all(x)) #define rsz resize #define ins insert #define pb push_back #define eb emplace_back #define ft front() #define bk back() #define rep(i, n) for (int i = 0; i < (n); ++i) #define rep1(i, n) for (int i = 1; i < (n); ++i) #define rep1n(i, n) for (int i = 1; i <= (n); ++i) #define repr(i, n) for (int i = (n) - 1; i >= 0; --i) #define rep_subset(t, s) \ for (ll t = (s); t >= 0; t = (t == 0 ? -1 : (t - 1) & (s))) #define lb lower_bound #define ub upper_bound template int lwb(vc &a, const T &b) { return int(lb(all(a), b) - bg(a)); } template int upb(vc &a, const T &b) { return int(ub(all(a), b) - bg(a)); } // const int MOD = 998244353; // 1e9+7; const int Big = 1e9; // not too close to INT_MAX const ll BIG = 1e18; // not too close to LLONG_MAX const db PI = acos((db)-1); const int dx[4]{1, 0, -1, 0}, dy[4]{0, 1, 0, -1}; // for every grid problem!! mt19937 rng((uint32_t)chrono::steady_clock::now().time_since_epoch().count()); template using pqg = priority_queue, greater>; int pct(int x) { return __builtin_popcount(x); } int pct(u32 x) { return __builtin_popcount(x); } int pct(ll x) { return __builtin_popcountll(x); } int pct(u64 x) { return __builtin_popcountll(x); } int popcnt_mod_2(int x) { return __builtin_parity(x); } int popcnt_mod_2(u32 x) { return __builtin_parity(x); } int popcnt_mod_2(ll x) { return __builtin_parityll(x); } int popcnt_mod_2(u64 x) { return __builtin_parityll(x); } // (0, 1, 2, 3, 4) -> (-1, 0, 1, 1, 2) int topbit(int x) { return (x == 0 ? -1 : 31 - __builtin_clz(x)); } int topbit(u32 x) { return (x == 0 ? -1 : 31 - __builtin_clz(x)); } int topbit(ll x) { return (x == 0 ? -1 : 63 - __builtin_clzll(x)); } int topbit(u64 x) { return (x == 0 ? -1 : 63 - __builtin_clzll(x)); } // (0, 1, 2, 3, 4) -> (-1, 0, 1, 0, 2) int lowbit(int x) { return (x == 0 ? -1 : __builtin_ctz(x)); } int lowbit(u32 x) { return (x == 0 ? -1 : __builtin_ctz(x)); } int lowbit(ll x) { return (x == 0 ? -1 : __builtin_ctzll(x)); } int lowbit(u64 x) { return (x == 0 ? -1 : __builtin_ctzll(x)); } template T floor(T a, T b) { return a / b - (a % b && (a ^ b) < 0); } template T ceil(T x, T y) { return floor(x + y - 1, y); } template T bmod(T x, T y) { return x - y * floor(x, y); } template pair divmod(T x, T y) { T q = floor(x, y); return {q, x - q * y}; } template bool ckmin(T &a, const T &b) { return b < a ? a = b, 1 : 0; } // set a = min(a,b) template bool ckmax(T &a, const T &b) { return a < b ? a = b, 1 : 0; } // set a = max(a,b) template T fstTrue(T lo, T hi, U f) { ++hi; assert(lo <= hi); // assuming f is increasing while (lo < hi) { // find first index such that f is true T mid = lo + (hi - lo) / 2; f(mid) ? hi = mid : lo = mid + 1; } return lo; } template T lstTrue(T lo, T hi, U f) { --lo; assert(lo <= hi); // assuming f is decreasing while (lo < hi) { // find first index such that f is true T mid = lo + (hi - lo + 1) / 2; f(mid) ? lo = mid : hi = mid - 1; } return lo; } template T extgcd(T a, T b, T &x, T &y) { if (a == 0) { x = 0; y = 1; return b; } T p = b / a; T g = extgcd(b - p * a, a, y, x); x -= p * y; return g; } template bool diophantine(T a, T b, T c, T &x, T &y, T &g) { if (a == 0 && b == 0) { if (c == 0) { x = y = g = 0; return true; } return false; } if (a == 0) { if (c % b == 0) { x = 0; y = c / b; g = abs(b); return true; } return false; } if (b == 0) { if (c % a == 0) { x = c / a; y = 0; g = abs(a); return true; } return false; } g = extgcd(a, b, x, y); if (c % g != 0) { return false; } T dx = c / a; c -= dx * a; T dy = c / b; c -= dy * b; x = dx + (T)((__int128)x * (c / g) % b); y = dy + (T)((__int128)y * (c / g) % a); g = abs(g); return true; // |x|, |y| <= max(|a|, |b|, |c|) [tested] } bool crt(long long k1, long long m1, long long k2, long long m2, long long &k, long long &m) { k1 %= m1; if (k1 < 0) k1 += m1; k2 %= m2; if (k2 < 0) k2 += m2; long long x, y, g; if (!diophantine(m1, -m2, k2 - k1, x, y, g)) { return false; } long long dx = m2 / g; long long delta = x / dx - (x % dx < 0); k = m1 * (x - dx * delta) + k1; m = m1 / g * m2; assert(0 <= k && k < m); return true; } // for distinct prime modulos template void crt_garner(const vector &p, const vector &a, T &res) { assert(p.size() == a.size()); auto inverse = [&](int q, int m) { q %= m; if (q < 0) q += m; int b = m, u = 0, v = 1; while (q) { int t = b / q; b -= t * q; swap(q, b); u -= t * v; swap(u, v); } assert(b == 1); if (u < 0) u += m; return u; }; vector x(p.size()); for (int i = 0; i < (int)p.size(); i++) { assert(0 <= a[i] && a[i] < p[i]); x[i] = a[i]; for (int j = 0; j < i; j++) { x[i] = (int)((long long)(x[i] - x[j]) * inverse(p[j], p[i]) % p[i]); if (x[i] < 0) x[i] += p[i]; } } res = 0; for (int i = (int)p.size() - 1; i >= 0; i--) { res = res * p[i] + x[i]; } } // signed main() { int main() { // freopen(".in", "r",stdin); // freopen(".out","w",stdout); ios::sync_with_stdio(false); cin.tie(0); int n; cin >> n; vc a(2, vi(n)); vc siz(2, vi(n)), top(2, vi(n, -1)), id(2, vi(n)), pre(2, vi(n)); for (int j = 0; j < 2; j++) { for (auto &i : a[j]) cin >> i, --i; for (int i = 0; i < n; i++) if (top[j][i] == -1) { top[j][i] = i, id[j][i] = 0, siz[j][i] = 1; int p = i, now = a[j][i]; while (now != i) { top[j][now] = i, id[j][now] = siz[j][i]++, pre[j][now] = p; p = now; now = a[j][now]; } pre[j][i] = p; } } map cyc; for (int i = 0; i < n; i++) { cyc[{top[0][i], top[1][i]}].eb(i); } const int MOD = 1e9 + 7; ll ans = 0; for (auto it : cyc) { debug(it); int lx = siz[0][it.fi.fi], ly = siz[1][it.fi.se]; int g = __gcd(lx, ly); auto i = it.se; map difs; for (auto j : i) { int wx = id[0][j], wy = id[1][j]; int dif = (wx - wy + ly) % g; wx = (wx - dif + lx) % lx; debug(wx, wy, dif); ll X = -1, Y; crt(wx, lx, wy, ly, X, Y); difs[dif].eb(X); } for (auto j : difs) { auto now = j.se; debug(j); if (now.empty()) continue; sor(now); now.eb(now.front() + 1ll * lx * ly / g); for (int x = 0; x < sz(now) - 1; x++) { ll now_dif = now[x + 1] - now[x]; now_dif %= MOD; ans += now_dif * (now_dif - 1 + MOD) % MOD * (MOD + 1) / 2 % MOD; ans %= MOD; } } } cout << ans << '\n'; return 0; }