/** * date : 2021-08-13 22:18:49 */ #define NDEBUG using namespace std; // intrinstic #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include // utility namespace Nyaan { using ll = long long; using i64 = long long; using u64 = unsigned long long; using i128 = __int128_t; using u128 = __uint128_t; template using V = vector; template using VV = vector>; using vi = vector; using vl = vector; using vd = V; using vs = V; using vvi = vector>; using vvl = vector>; template struct P : pair { template P(Args... args) : pair(args...) {} using pair::first; using pair::second; T &x() { return first; } const T &x() const { return first; } U &y() { return second; } const U &y() const { return second; } P &operator+=(const P &r) { first += r.first; second += r.second; return *this; } P &operator-=(const P &r) { first -= r.first; second -= r.second; return *this; } P &operator*=(const P &r) { first *= r.first; second *= r.second; return *this; } P operator+(const P &r) const { return P(*this) += r; } P operator-(const P &r) const { return P(*this) -= r; } P operator*(const P &r) const { return P(*this) *= r; } }; using pl = P; using pi = P; using vp = V; constexpr int inf = 1001001001; constexpr long long infLL = 4004004004004004004LL; template int sz(const T &t) { return t.size(); } template inline bool amin(T &x, U y) { return (y < x) ? (x = y, true) : false; } template inline bool amax(T &x, U y) { return (x < y) ? (x = y, true) : false; } template inline T Max(const vector &v) { return *max_element(begin(v), end(v)); } template inline T Min(const vector &v) { return *min_element(begin(v), end(v)); } template inline long long Sum(const vector &v) { return accumulate(begin(v), end(v), 0LL); } template int lb(const vector &v, const T &a) { return lower_bound(begin(v), end(v), a) - begin(v); } template int ub(const vector &v, const T &a) { return upper_bound(begin(v), end(v), a) - begin(v); } constexpr long long TEN(int n) { long long ret = 1, x = 10; for (; n; x *= x, n >>= 1) ret *= (n & 1 ? x : 1); return ret; } template pair mkp(const T &t, const U &u) { return make_pair(t, u); } template vector mkrui(const vector &v, bool rev = false) { vector ret(v.size() + 1); if (rev) { for (int i = int(v.size()) - 1; i >= 0; i--) ret[i] = v[i] + ret[i + 1]; } else { for (int i = 0; i < int(v.size()); i++) ret[i + 1] = ret[i] + v[i]; } return ret; }; template vector mkuni(const vector &v) { vector ret(v); sort(ret.begin(), ret.end()); ret.erase(unique(ret.begin(), ret.end()), ret.end()); return ret; } template vector mkord(int N, F f) { vector ord(N); iota(begin(ord), end(ord), 0); sort(begin(ord), end(ord), f); return ord; } template vector mkinv(vector &v) { int max_val = *max_element(begin(v), end(v)); vector inv(max_val + 1, -1); for (int i = 0; i < (int)v.size(); i++) inv[v[i]] = i; return inv; } } // namespace Nyaan // bit operation namespace Nyaan { __attribute__((target("popcnt"))) inline int popcnt(const u64 &a) { return _mm_popcnt_u64(a); } inline int lsb(const u64 &a) { return a ? __builtin_ctzll(a) : 64; } inline int ctz(const u64 &a) { return a ? __builtin_ctzll(a) : 64; } inline int msb(const u64 &a) { return a ? 63 - __builtin_clzll(a) : -1; } template inline int gbit(const T &a, int i) { return (a >> i) & 1; } template inline void sbit(T &a, int i, bool b) { if (gbit(a, i) != b) a ^= T(1) << i; } constexpr long long PW(int n) { return 1LL << n; } constexpr long long MSK(int n) { return (1LL << n) - 1; } } // namespace Nyaan // inout namespace Nyaan { template ostream &operator<<(ostream &os, const pair &p) { os << p.first << " " << p.second; return os; } template istream &operator>>(istream &is, pair &p) { is >> p.first >> p.second; return is; } template ostream &operator<<(ostream &os, const vector &v) { int s = (int)v.size(); for (int i = 0; i < s; i++) os << (i ? " " : "") << v[i]; return os; } template istream &operator>>(istream &is, vector &v) { for (auto &x : v) is >> x; return is; } void in() {} template void in(T &t, U &... u) { cin >> t; in(u...); } void out() { cout << "\n"; } template void out(const T &t, const U &... u) { cout << t; if (sizeof...(u)) cout << sep; out(u...); } void outr() {} template void outr(const T &t, const U &... u) { cout << t; outr(u...); } struct IoSetupNya { IoSetupNya() { cin.tie(nullptr); ios::sync_with_stdio(false); cout << fixed << setprecision(15); cerr << fixed << setprecision(7); } } iosetupnya; } // namespace Nyaan // debug namespace DebugImpl { template struct is_specialize : false_type {}; template struct is_specialize< U, typename conditional::type> : true_type {}; template struct is_specialize< U, typename conditional::type> : true_type {}; template struct is_specialize::value, void>> : true_type { }; void dump(const char& t) { cerr << t; } void dump(const string& t) { cerr << t; } void dump(const bool& t) { cerr << (t ? "true" : "false"); } template ::value, nullptr_t> = nullptr> void dump(const U& t) { cerr << t; } template void dump(const T& t, enable_if_t::value>* = nullptr) { string res; if (t == Nyaan::inf) res = "inf"; if constexpr (is_signed::value) { if (t == -Nyaan::inf) res = "-inf"; } if constexpr (sizeof(T) == 8) { if (t == Nyaan::infLL) res = "inf"; if constexpr (is_signed::value) { if (t == -Nyaan::infLL) res = "-inf"; } } if (res.empty()) res = to_string(t); cerr << res; } template void dump(const pair&); template void dump(const pair&); template void dump(const T& t, enable_if_t::value>* = nullptr) { cerr << "[ "; for (auto it = t.begin(); it != t.end();) { dump(*it); cerr << (++it == t.end() ? "" : ", "); } cerr << " ]"; } template void dump(const pair& t) { cerr << "( "; dump(t.first); cerr << ", "; dump(t.second); cerr << " )"; } template void dump(const pair& t) { cerr << "[ "; for (int i = 0; i < t.second; i++) { dump(t.first[i]); cerr << (i == t.second - 1 ? "" : ", "); } cerr << " ]"; } void trace() { cerr << endl; } template void trace(Head&& head, Tail&&... tail) { cerr << " "; dump(head); if (sizeof...(tail) != 0) cerr << ","; trace(forward(tail)...); } } // namespace DebugImpl #ifdef NyaanDebug #define trc(...) \ do { \ cerr << "## " << #__VA_ARGS__ << " = "; \ DebugImpl::trace(__VA_ARGS__); \ } while (0) #else #define trc(...) (void(0)) #endif // macro #define each(x, v) for (auto&& x : v) #define each2(x, y, v) for (auto&& [x, y] : v) #define all(v) (v).begin(), (v).end() #define rep(i, N) for (long long i = 0; i < (long long)(N); i++) #define repr(i, N) for (long long i = (long long)(N)-1; i >= 0; i--) #define rep1(i, N) for (long long i = 1; i <= (long long)(N); i++) #define repr1(i, N) for (long long i = (N); (long long)(i) > 0; i--) #define reg(i, a, b) for (long long i = (a); i < (b); i++) #define regr(i, a, b) for (long long i = (b)-1; i >= (a); i--) #define fi first #define se second #define ini(...) \ int __VA_ARGS__; \ in(__VA_ARGS__) #define inl(...) \ long long __VA_ARGS__; \ in(__VA_ARGS__) #define ins(...) \ string __VA_ARGS__; \ in(__VA_ARGS__) #define in2(s, t) \ for (int i = 0; i < (int)s.size(); i++) { \ in(s[i], t[i]); \ } #define in3(s, t, u) \ for (int i = 0; i < (int)s.size(); i++) { \ in(s[i], t[i], u[i]); \ } #define in4(s, t, u, v) \ for (int i = 0; i < (int)s.size(); i++) { \ in(s[i], t[i], u[i], v[i]); \ } #define die(...) \ do { \ Nyaan::out(__VA_ARGS__); \ return; \ } while (0) namespace Nyaan { void solve(); } int main() { Nyaan::solve(); } // namespace HashMapImpl { using u32 = uint32_t; using u64 = uint64_t; template struct HashMapBase; template struct itrB : iterator { using base = iterator; using ptr = typename base::pointer; using ref = typename base::reference; u32 i; HashMapBase* p; explicit constexpr itrB() : i(0), p(nullptr) {} explicit constexpr itrB(u32 _i, HashMapBase* _p) : i(_i), p(_p) {} explicit constexpr itrB(u32 _i, const HashMapBase* _p) : i(_i), p(const_cast*>(_p)) {} friend void swap(itrB& l, itrB& r) { swap(l.i, r.i), swap(l.p, r.p); } friend bool operator==(const itrB& l, const itrB& r) { return l.i == r.i; } friend bool operator!=(const itrB& l, const itrB& r) { return l.i != r.i; } const ref operator*() const { return const_cast*>(p)->data[i]; } ref operator*() { return p->data[i]; } ptr operator->() const { return &(p->data[i]); } itrB& operator++() { assert(i != p->cap && "itr::operator++()"); do { i++; if (i == p->cap) break; if (p->flag[i] == true && p->dflag[i] == false) break; } while (true); return (*this); } itrB operator++(int) { itrB it(*this); ++(*this); return it; } itrB& operator--() { do { i--; if (p->flag[i] == true && p->dflag[i] == false) break; assert(i != 0 && "itr::operator--()"); } while (true); return (*this); } itrB operator--(int) { itrB it(*this); --(*this); return it; } }; template struct HashMapBase { using u32 = uint32_t; using u64 = uint64_t; using iterator = itrB; using itr = iterator; protected: template inline u64 randomized(const K& key) const { return u64(key) ^ r; } template ::value, nullptr_t> = nullptr, enable_if_t::value, nullptr_t> = nullptr> inline u32 inner_hash(const K& key) const { return (randomized(key) * 11995408973635179863ULL) >> shift; } template < typename K, enable_if_t::value, nullptr_t> = nullptr, enable_if_t::value, nullptr_t> = nullptr, enable_if_t::value, nullptr_t> = nullptr> inline u32 inner_hash(const K& key) const { u64 a = randomized(key.first), b = randomized(key.second); a *= 11995408973635179863ULL; b *= 10150724397891781847ULL; return (a + b) >> shift; } template ::value, nullptr_t> = nullptr, enable_if_t::value, nullptr_t> = nullptr> inline u32 inner_hash(const K& key) const { static constexpr u64 mod = (1LL << 61) - 1; static constexpr u64 base = 950699498548472943ULL; u64 res = 0; for (auto& elem : key) { __uint128_t x = __uint128_t(res) * base + (randomized(elem) & mod); res = (x & mod) + (x >> 61); } __uint128_t x = __uint128_t(res) * base; res = (x & mod) + (x >> 61); if (res >= mod) res -= mod; return res >> (shift - 3); } template ::value, nullptr_t> = nullptr> inline u32 hash(const D& dat) const { return inner_hash(dat); } template < typename D = Data, enable_if_t::value, nullptr_t> = nullptr> inline u32 hash(const D& dat) const { return inner_hash(dat.first); } template ::value, nullptr_t> = nullptr> inline Key dtok(const D& dat) const { return dat; } template < typename D = Data, enable_if_t::value, nullptr_t> = nullptr> inline Key dtok(const D& dat) const { return dat.first; } void reallocate(u32 ncap) { vector ndata(ncap); vector nf(ncap); shift = 64 - __lg(ncap); for (u32 i = 0; i < cap; i++) { if (flag[i] == true && dflag[i] == false) { u32 h = hash(data[i]); while (nf[h]) h = (h + 1) & (ncap - 1); ndata[h] = move(data[i]); nf[h] = true; } } data.swap(ndata); flag.swap(nf); cap = ncap; dflag.resize(cap); fill(std::begin(dflag), std::end(dflag), false); } inline bool extend_rate(u32 x) const { return x * 2 >= cap; } inline bool shrink_rate(u32 x) const { return HASHMAP_DEFAULT_SIZE < cap && x * 10 <= cap; } inline void extend() { reallocate(cap << 1); } inline void shrink() { reallocate(cap >> 1); } public: u32 cap, s; vector data; vector flag, dflag; u32 shift; static u64 r; static constexpr uint32_t HASHMAP_DEFAULT_SIZE = 4; explicit HashMapBase() : cap(HASHMAP_DEFAULT_SIZE), s(0), data(cap), flag(cap), dflag(cap), shift(64 - __lg(cap)) {} itr begin() const { u32 h = 0; while (h != cap) { if (flag[h] == true && dflag[h] == false) break; h++; } return itr(h, this); } itr end() const { return itr(this->cap, this); } friend itr begin(const HashMapBase& h) { return h.begin(); } friend itr end(const HashMapBase& h) { return h.end(); } itr find(const Key& key) const { u32 h = inner_hash(key); while (true) { if (flag[h] == false) return this->end(); if (dtok(data[h]) == key) { if (dflag[h] == true) return this->end(); return itr(h, this); } h = (h + 1) & (cap - 1); } } bool contain(const Key& key) const { return find(key) != this->end(); } itr insert(const Data& d) { u32 h = hash(d); while (true) { if (flag[h] == false) { if (extend_rate(s + 1)) { extend(); h = hash(d); continue; } data[h] = d; flag[h] = true; ++s; return itr(h, this); } if (dtok(data[h]) == dtok(d)) { if (dflag[h] == true) { data[h] = d; dflag[h] = false; ++s; } return itr(h, this); } h = (h + 1) & (cap - 1); } } // tips for speed up : // if return value is unnecessary, make argument_2 false. itr erase(itr it, bool get_next = true) { if (it == this->end()) return this->end(); s--; if (shrink_rate(s)) { Data d = data[it.i]; shrink(); it = find(dtok(d)); } int ni = (it.i + 1) & (cap - 1); if (this->flag[ni]) { this->dflag[it.i] = true; } else { this->flag[it.i] = false; } if (get_next) ++it; return it; } itr erase(const Key& key) { return erase(find(key)); } bool empty() const { return s == 0; } int size() const { return s; } void clear() { fill(std::begin(flag), std::end(flag), false); fill(std::begin(dflag), std::end(dflag), false); s = 0; } void reserve(int n) { if (n <= 0) return; n = 1 << min(23, __lg(n) + 2); if (cap < u32(n)) reallocate(n); } }; template uint64_t HashMapBase::r = chrono::duration_cast( chrono::high_resolution_clock::now().time_since_epoch()) .count(); } // namespace HashMapImpl /** * @brief Hash Map(base) (ハッシュマップ・基底クラス) */ template struct HashMap : HashMapImpl::HashMapBase> { using base = typename HashMapImpl::HashMapBase>; using HashMapImpl::HashMapBase>::HashMapBase; using Data = pair; Val& operator[](const Key& k) { typename base::u32 h = base::inner_hash(k); while (true) { if (base::flag[h] == false) { if (base::extend_rate(base::s + 1)) { base::extend(); h = base::hash(k); continue; } base::data[h].first = k; base::data[h].second = Val(); base::flag[h] = true; ++base::s; return base::data[h].second; } if (base::data[h].first == k) { if (base::dflag[h] == true) base::data[h].second = Val(); return base::data[h].second; } h = (h + 1) & (base::cap - 1); } } typename base::itr emplace(const Key& key, const Val& val) { return base::insert(Data(key, val)); } }; /* * @brief ハッシュマップ(連想配列) * @docs docs/hashmap/hashmap.md **/ // namespace inner { using i32 = int32_t; using u32 = uint32_t; using i64 = int64_t; using u64 = uint64_t; template T gcd(T a, T b) { while (b) swap(a %= b, b); return a; } template T inv(T a, T p) { T b = p, x = 1, y = 0; while (a) { T q = b / a; swap(a, b %= a); swap(x, y -= q * x); } assert(b == 1); return y < 0 ? y + p : y; } template T modpow(T a, U n, T p) { T ret = 1 % p; for (; n; n >>= 1, a = U(a) * a % p) if (n & 1) ret = U(ret) * a % p; return ret; } } // namespace inner int64_t mod_log(int64_t a, int64_t b, int64_t p) { using namespace inner; if ((a %= p) < 0) a += p; if ((b %= p) < 0) b += p; int64_t f, g, r = 1 % p; for (f = 0; (g = gcd(a, p)) > 1; ++f) { if (b % g) return (r == b) ? f : -1; b /= g; p /= g; (r *= (a / g)) %= p; } if (p == 1) return f; int64_t ir = inv(r, p); (b *= ir) %= p; int64_t k = 0, ak = 1; HashMap baby; for (; k * k < p; ++k) { if(baby.find(ak) == baby.end()) baby[ak] = k; (ak *= a) %= p; } int64_t iak = inv(ak, p); for (int64_t i = 0; i < k; ++i) { if (baby.find(b) != baby.end()) return f + i * k + baby[b]; (b *= iak) %= p; } return -1; } // template std::pair GaussElimination(vector> &a, int pivot_end = -1, bool diagonalize = false) { int H = a.size(), W = a[0].size(); int rank = 0, je = pivot_end; if (je == -1) je = W; mint det = 1; for (int j = 0; j < je; j++) { int idx = -1; for (int i = rank; i < H; i++) { if (a[i][j] != mint(0)) { idx = i; break; } } if (idx == -1) { det = 0; continue; } if (rank != idx) { det = -det; swap(a[rank], a[idx]); } det *= a[rank][j]; if (diagonalize && a[rank][j] != mint(1)) { mint coeff = a[rank][j].inverse(); for (int k = j; k < W; k++) a[rank][k] *= coeff; } int is = diagonalize ? 0 : rank + 1; for (int i = is; i < H; i++) { if (i == rank) continue; if (a[i][j] != mint(0)) { mint coeff = a[i][j] / a[rank][j]; for (int k = j; k < W; k++) a[i][k] -= a[rank][k] * coeff; } } rank++; } return make_pair(rank, det); } template vector> inverse_matrix(const vector>& a) { int N = a.size(); assert(N > 0); assert(N == (int)a[0].size()); vector> m(N, vector(2 * N)); for (int i = 0; i < N; i++) { copy(begin(a[i]), end(a[i]), begin(m[i])); m[i][N + i] = 1; } auto [rank, det] = GaussElimination(m, N, true); if (rank != N) return {}; vector> b(N); for (int i = 0; i < N; i++) { copy(begin(m[i]) + N, end(m[i]), back_inserter(b[i])); } return b; } template struct Matrix { vector > A; Matrix() = default; Matrix(int n, int m) : A(n, vector(m, T())) {} Matrix(int n) : A(n, vector(n, T())){}; int H() const { return A.size(); } int W() const { return A[0].size(); } int size() const { return A.size(); } inline const vector &operator[](int k) const { return A[k]; } inline vector &operator[](int k) { return A[k]; } static Matrix I(int n) { Matrix mat(n); for (int i = 0; i < n; i++) mat[i][i] = 1; return (mat); } Matrix &operator+=(const Matrix &B) { int n = H(), m = W(); assert(n == B.H() && m == B.W()); for (int i = 0; i < n; i++) for (int j = 0; j < m; j++) (*this)[i][j] += B[i][j]; return (*this); } Matrix &operator-=(const Matrix &B) { int n = H(), m = W(); assert(n == B.H() && m == B.W()); for (int i = 0; i < n; i++) for (int j = 0; j < m; j++) (*this)[i][j] -= B[i][j]; return (*this); } Matrix &operator*=(const Matrix &B) { int n = H(), m = B.W(), p = W(); assert(p == B.H()); vector > C(n, vector(m, T{})); for (int i = 0; i < n; i++) for (int k = 0; k < p; k++) for (int j = 0; j < m; j++) C[i][j] += (*this)[i][k] * B[k][j]; A.swap(C); return (*this); } Matrix &operator^=(long long k) { Matrix B = Matrix::I(H()); while (k > 0) { if (k & 1) B *= *this; *this *= *this; k >>= 1LL; } A.swap(B.A); return (*this); } Matrix operator+(const Matrix &B) const { return (Matrix(*this) += B); } Matrix operator-(const Matrix &B) const { return (Matrix(*this) -= B); } Matrix operator*(const Matrix &B) const { return (Matrix(*this) *= B); } Matrix operator^(const long long k) const { return (Matrix(*this) ^= k); } bool operator==(const Matrix &B) const { assert(H() == B.H() && W() == B.W()); for (int i = 0; i < H(); i++) for (int j = 0; j < W(); j++) if (A[i][j] != B[i][j]) return false; return true; } bool operator!=(const Matrix &B) const { assert(H() == B.H() && W() == B.W()); for (int i = 0; i < H(); i++) for (int j = 0; j < W(); j++) if (A[i][j] != B[i][j]) return true; return false; } friend ostream &operator<<(ostream &os, const Matrix &p) { int n = p.H(), m = p.W(); for (int i = 0; i < n; i++) { os << (i ? " " : "") << "["; for (int j = 0; j < m; j++) { os << p[i][j] << (j + 1 == m ? "]\n" : ","); } } return (os); } T determinant() const { Matrix B(*this); assert(H() == W()); T ret = 1; for (int i = 0; i < H(); i++) { int idx = -1; for (int j = i; j < W(); j++) { if (B[j][i] != 0) { idx = j; break; } } if (idx == -1) return 0; if (i != idx) { ret *= T(-1); swap(B[i], B[idx]); } ret *= B[i][i]; T inv = T(1) / B[i][i]; for (int j = 0; j < W(); j++) { B[i][j] *= inv; } for (int j = i + 1; j < H(); j++) { T a = B[j][i]; if (a == 0) continue; for (int k = i; k < W(); k++) { B[j][k] -= B[i][k] * a; } } } return ret; } }; /** * @brief 行列ライブラリ */ template struct LazyMontgomeryModInt { using mint = LazyMontgomeryModInt; using i32 = int32_t; using u32 = uint32_t; using u64 = uint64_t; static constexpr u32 get_r() { u32 ret = mod; for (i32 i = 0; i < 4; ++i) ret *= 2 - mod * ret; return ret; } static constexpr u32 r = get_r(); static constexpr u32 n2 = -u64(mod) % mod; static_assert(r * mod == 1, "invalid, r * mod != 1"); static_assert(mod < (1 << 30), "invalid, mod >= 2 ^ 30"); static_assert((mod & 1) == 1, "invalid, mod % 2 == 0"); u32 a; constexpr LazyMontgomeryModInt() : a(0) {} constexpr LazyMontgomeryModInt(const int64_t &b) : a(reduce(u64(b % mod + mod) * n2)){}; static constexpr u32 reduce(const u64 &b) { return (b + u64(u32(b) * u32(-r)) * mod) >> 32; } constexpr mint &operator+=(const mint &b) { if (i32(a += b.a - 2 * mod) < 0) a += 2 * mod; return *this; } constexpr mint &operator-=(const mint &b) { if (i32(a -= b.a) < 0) a += 2 * mod; return *this; } constexpr mint &operator*=(const mint &b) { a = reduce(u64(a) * b.a); return *this; } constexpr mint &operator/=(const mint &b) { *this *= b.inverse(); return *this; } constexpr mint operator+(const mint &b) const { return mint(*this) += b; } constexpr mint operator-(const mint &b) const { return mint(*this) -= b; } constexpr mint operator*(const mint &b) const { return mint(*this) *= b; } constexpr mint operator/(const mint &b) const { return mint(*this) /= b; } constexpr bool operator==(const mint &b) const { return (a >= mod ? a - mod : a) == (b.a >= mod ? b.a - mod : b.a); } constexpr bool operator!=(const mint &b) const { return (a >= mod ? a - mod : a) != (b.a >= mod ? b.a - mod : b.a); } constexpr mint operator-() const { return mint() - mint(*this); } constexpr mint pow(u64 n) const { mint ret(1), mul(*this); while (n > 0) { if (n & 1) ret *= mul; mul *= mul; n >>= 1; } return ret; } constexpr mint inverse() const { return pow(mod - 2); } friend ostream &operator<<(ostream &os, const mint &b) { return os << b.get(); } friend istream &operator>>(istream &is, mint &b) { int64_t t; is >> t; b = LazyMontgomeryModInt(t); return (is); } constexpr u32 get() const { u32 ret = reduce(a); return ret >= mod ? ret - mod : ret; } static constexpr u32 get_mod() { return mod; } }; // using namespace Nyaan; using mint = LazyMontgomeryModInt<998244353>; // using mint = LazyMontgomeryModInt<1000000007>; using vm = vector; using vvm = vector; using namespace Nyaan; using mat = Matrix; void Nyaan::solve() { inl(A, B, P, Q); if (B == 0) { if (A == 0) { out(2); return; } ll ans = mod_log(A, P, 998244353); if (ans <= 1) ans += 998244352; out(ans); return; } ll BUC = TEN(5); mat M(2); M[0][0] = A, M[0][1] = -B, M[1][0] = 1; HashMap, ll> memo; mat MM; mat S1(2, 1); S1[0][0] = A, S1[1][0] = 2; mat PQ(2, 1); PQ[0][0] = P, PQ[1][0] = Q; { mat a = mat::I(2); rep(i, BUC) { auto b = a * S1; vi v(2); v[0] = b[0][0].get(), v[1] = b[1][0].get(); memo[make_pair(v[0], v[1])] = i; a *= M; } MM = a; } MM.A = inverse_matrix(MM.A); mat base = mat::I(2); for (ll i = 0;; i++) { trc(i); mat inv{base}; mat mt = inv * PQ; vi v(2); v[0] = mt[0][0].get(), v[1] = mt[1][0].get(); auto p = make_pair(v[0], v[1]); if (memo.find(p) != memo.end()) { if (i * BUC + memo[p] + 1 != 1) { out(i * BUC + memo[p] + 1); exit(0); } } base *= MM; } }