#include using namespace std; #define REP(i, n) for(int i = 0; i < (n); i++) //ModInt template struct ModInt { private: int x; public: ModInt() : x(0) {} ModInt(long long x_) { if((x = x_ % mod + mod) >= mod) x -= mod; } int val() const { return x; } static int get_mod() { return mod; } constexpr ModInt &operator+=(ModInt rhs) { if((x += rhs.x) >= mod) x -= mod; return *this; } constexpr ModInt &operator-=(ModInt rhs) { if((x -= rhs.x) < 0) x += mod; return *this; } constexpr ModInt &operator*=(ModInt rhs) { x = (unsigned long long)x * rhs.x % mod; return *this; } constexpr ModInt &operator/=(ModInt rhs) { x = (unsigned long long)x * rhs.inv().x % mod; return *this; } constexpr ModInt operator-() const noexcept { return -x < 0 ? mod - x : -x; } constexpr ModInt operator+(ModInt rhs) const noexcept { return ModInt(*this) += rhs; } constexpr ModInt operator-(ModInt rhs) const noexcept { return ModInt(*this) -= rhs; } constexpr ModInt operator*(ModInt rhs) const noexcept { return ModInt(*this) *= rhs; } constexpr ModInt operator/(ModInt rhs) const noexcept { return ModInt(*this) /= rhs; } constexpr ModInt &operator++() { *this += 1; return *this; } constexpr ModInt operator++(int) { *this += 1; return *this - 1; } constexpr ModInt &operator--() { *this -= 1; return *this; } constexpr ModInt operator--(int) { *this -= 1; return *this + 1; } bool operator==(ModInt rhs) const { return x == rhs.x; } bool operator!=(ModInt rhs) const { return x != rhs.x; } bool operator<=(ModInt rhs) const { return x <= rhs.x; } bool operator>=(ModInt rhs) const { return x >= rhs.x; } bool operator<(ModInt rhs) const { return x < rhs.x; } bool operator>(ModInt rhs) const { return x > rhs.x; } ModInt inv() { int a = x, b = mod, u = 1, v = 0, t; while(b > 0) { t = a / b; std::swap(a -= t * b, b); std::swap(u -= t * v, v); } return ModInt(u); } ModInt pow(long long n) const { ModInt ret(1), mul(x); while(n > 0) { if(n & 1) ret *= mul; mul *= mul; n >>= 1; } return ret; } ModInt sqrt() const { if(x <= 1) return x; int v = (mod - 1) / 2; if(pow(v) != 1) return -1; int q = mod - 1, m = 0; while(~q & 1) q >>= 1, m++; std::mt19937 mt; ModInt z = mt(); while(z.pow(v) != mod - 1) z = mt(); ModInt c = z.pow(q), t = pow(q), r = pow((q + 1) / 2); for(; m > 1; m--) { ModInt tmp = t.pow(1 << (m - 2)); if(tmp != 1) r = r * c, t = t * c * c; c = c * c; } return std::min(r.x, mod - r.x); } friend std::ostream &operator<<(std::ostream &s, ModInt a) { s << a.x; return s; } friend std::istream &operator>>(std::istream &s, ModInt &a) { s >> a.x; return s; } }; //Modulo Calculation static int MOD = 998244353; using mint = ModInt; struct NumberTheoreticTransformFriendlyModInt { std::vector dw, idw; int max_base; mint root; NumberTheoreticTransformFriendlyModInt() { const unsigned mod = mint::get_mod(); assert(mod >= 3 && mod % 2 == 1); auto tmp = mod - 1; max_base = 0; while(tmp % 2 == 0) tmp >>= 1, max_base++; root = 2; while(root.pow((mod - 1) >> 1) == 1) root += 1; assert(root.pow(mod - 1) == 1); dw.resize(max_base); idw.resize(max_base); for(int i = 0; i < max_base; i++) { dw[i] = -root.pow((mod - 1) >> (i + 2)); idw[i] = mint(1) / dw[i]; } } void ntt(std::vector &a) { const int n = (int)a.size(); assert((n & (n - 1)) == 0); assert(__builtin_ctz(n) <= max_base); for(int m = n; m >>= 1;) { mint w = 1; for(int s = 0, k = 0; s < n; s += 2 * m) { for(int i = s, j = s + m; i < s + m; ++i, ++j) { mint x = a[i], y = a[j] * w; a[i] = x + y, a[j] = x - y; } w *= dw[__builtin_ctz(++k)]; } } } void intt(std::vector &a, bool f = true) { const int n = (int)a.size(); assert((n & (n - 1)) == 0); assert(__builtin_ctz(n) <= max_base); for(int m = 1; m < n; m *= 2) { mint w = 1; for(int s = 0, k = 0; s < n; s += 2 * m) { for(int i = s, j = s + m; i < s + m; ++i, ++j) { mint x = a[i], y = a[j]; a[i] = x + y, a[j] = (x - y) * w; } w *= idw[__builtin_ctz(++k)]; } } if(f) { mint inv_sz = mint(1) / n; for(int i = 0; i < n; i++) a[i] *= inv_sz; } } std::vector multiply(std::vector a, std::vector b) { int need = a.size() + b.size() - 1; int nbase = 1; while((1 << nbase) < need) nbase++; int sz = 1 << nbase; a.resize(sz, 0); b.resize(sz, 0); ntt(a); ntt(b); mint inv_sz = mint(1) / sz; for(int i = 0; i < sz; i++) a[i] *= b[i] * inv_sz; intt(a, false); a.resize(need); return a; } }; struct FormalPowerSeries : std::vector { using std::vector::vector; using P = FormalPowerSeries; using MULT = std::function; using FFT = std::function; using SQRT = std::function; static MULT &get_mult() { static MULT mult = nullptr; return mult; } static void set_mult(MULT f) { get_mult() = f; } static FFT &get_fft() { static FFT fft = nullptr; return fft; } static FFT &get_ifft() { static FFT ifft = nullptr; return ifft; } static void set_fft(FFT f, FFT g) { get_fft() = f; get_ifft() = g; } static SQRT &get_sqrt() { static SQRT sqr = nullptr; return sqr; } static void set_sqrt(SQRT sqr) { get_sqrt() = sqr; } void shrink() { while(this->size() && this->back() == mint(0)) this->pop_back(); } P operator+(const P &r) const { return P(*this) += r; } P operator+(const mint &v) const { return P(*this) += v; } P operator-(const P &r) const { return P(*this) -= r; } P operator-(const mint &v) const { return P(*this) -= v; } P operator*(const P &r) const { return P(*this) *= r; } P operator*(const mint &v) const { return P(*this) *= v; } 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) { if(r.size() > this->size()) this->resize(r.size()); for(int i = 0; i < r.size(); i++) (*this)[i] += r[i]; return *this; } P &operator+=(const mint &r) { if(this->empty()) this->resize(1); (*this)[0] += r; return *this; } P &operator-=(const P &r) { if(r.size() > this->size()) this->resize(r.size()); for(int i = 0; i < r.size(); i++) (*this)[i] -= r[i]; shrink(); return *this; } P &operator-=(const mint &r) { if(this->empty()) this->resize(1); (*this)[0] -= r; shrink(); return *this; } P &operator*=(const mint &v) { const int n = (int)this->size(); for(int k = 0; k < n; k++) (*this)[k] *= v; return *this; } P &operator*=(const P &r) { if(this->empty() || r.empty()) { this->clear(); return *this; } assert(get_mult() != nullptr); return *this = get_mult()(*this, r); } P &operator%=(const P &r) { return *this -= *this / r * r; } P operator-() const { P ret(this->size()); for(int i = 0; i < this->size(); i++) ret[i] = -(*this)[i]; return ret; } P &operator/=(const P &r) { if(this->size() < r.size()) { this->clear(); return *this; } int n = this->size() - r.size() + 1; return *this = (rev().pre(n) * r.rev().inv(n)).pre(n).rev(n); } P dot(P r) const { P ret(std::min(this->size(), r.size())); for(int i = 0; i < ret.size(); i++) ret[i] = (*this)[i] * r[i]; return ret; } P pre(int sz) const { return P(std::begin(*this), std::begin(*this) + std::min((int)this->size(), sz)); } P operator>>(int sz) const { if(this->size() <= sz) return {}; P ret(*this); ret.erase(ret.begin(), ret.begin() + sz); return ret; } P operator<<(int sz) const { P ret(*this); ret.insert(ret.begin(), sz, mint(0)); return ret; } P rev(int deg = -1) const { P ret(*this); if(deg != -1) ret.resize(deg, mint(0)); std::reverse(std::begin(ret), std::end(ret)); return ret; } P diff() const { const int n = (int)this->size(); P ret(std::max(0, n - 1)); for(int i = 1; i < n; i++) ret[i - 1] = (*this)[i] * mint(i); return ret; } P integral() const { const int n = (int)this->size(); P ret(n + 1); ret[0] = mint(0); for(int i = 0; i < n; i++) ret[i + 1] = (*this)[i] / mint(i + 1); return ret; } // F(0) must not be 0 P inv(int deg = -1) const { assert(((*this)[0]) != mint(0)); const int n = (int)this->size(); if(deg == -1) deg = n; if(get_fft() != nullptr) { P ret(*this); ret.resize(deg, mint(0)); return ret.inv_fast(); } P ret({mint(1) / (*this)[0]}); for(int i = 1; i < deg; i <<= 1) { ret = (ret + ret - ret * ret * pre(i << 1)).pre(i << 1); } return ret.pre(deg); } // F(0) must be 1 P log(int deg = -1) const { assert((*this)[0] == 1); const int n = (int)this->size(); if(deg == -1) deg = n; return (this->diff() * this->inv(deg)).pre(deg - 1).integral(); } P sqrt(int deg = -1) const { const int n = (int)this->size(); if(deg == -1) deg = n; if((*this)[0] == mint(0)) { for(int i = 1; i < n; i++) { if((*this)[i] != mint(0)) { if(i & 1) return {}; if(deg - i / 2 <= 0) break; auto ret = (*this >> i).sqrt(deg - i / 2); if(ret.empty()) return {}; ret = ret << (i / 2); if(ret.size() < deg) ret.resize(deg, mint(0)); return ret; } } return P(deg, 0); } P ret; if(get_sqrt() == nullptr) { assert((*this)[0] == mint(1)); ret = {mint(1)}; } else { auto sqr = get_sqrt()((*this)[0]); if(sqr * sqr != (*this)[0]) return {}; ret = {mint(sqr)}; } mint inv2 = mint(1) / mint(2); for(int i = 1; i < deg; i <<= 1) { ret = (ret + pre(i << 1) * ret.inv(i << 1)) * inv2; } return ret.pre(deg); } // F(0) must be 0 P exp(int deg = -1) const { assert((*this)[0] == mint(0)); const int n = (int)this->size(); if(deg == -1) deg = n; if(get_fft() != nullptr) { P ret(*this); ret.resize(deg, mint(0)); return ret.exp_rec(); } P ret({mint(1)}); for(int i = 1; i < deg; i <<= 1) { ret = (ret * (pre(i << 1) + mint(1) - ret.log(i << 1))).pre(i << 1); } return ret.pre(deg); } P online_convolution_exp(const P &conv_coeff) const { const int n = (int)conv_coeff.size(); assert((n & (n - 1)) == 0); vector

conv_ntt_coeff; auto &fft = get_fft(); auto &ifft = get_ifft(); for(int i = n; i >= 1; i >>= 1) { P g(conv_coeff.pre(i)); fft(g); conv_ntt_coeff.emplace_back(g); } P conv_arg(n), conv_ret(n); auto rec = [&](auto rec, int l, int r, int d) -> void { if(r - l <= 16) { for(int i = l; i < r; i++) { mint sum = 0; for(int j = l; j < i; j++) sum += conv_arg[j] * conv_coeff[i - j]; conv_ret[i] += sum; conv_arg[i] = i == 0 ? mint(1) : conv_ret[i] / i; } } else { int m = (l + r) / 2; rec(rec, l, m, d + 1); P pre(r - l); for(int i = 0; i < m - l; i++) pre[i] = conv_arg[l + i]; fft(pre); for(int i = 0; i < r - l; i++) pre[i] *= conv_ntt_coeff[d][i]; ifft(pre); for(int i = 0; i < r - m; i++) conv_ret[m + i] += pre[m + i - l]; rec(rec, m, r, d + 1); } }; rec(rec, 0, n, 0); return conv_arg; } P exp_rec() const { assert((*this)[0] == mint(0)); const int n = (int)this->size(); int m = 1; while(m < n) m *= 2; P conv_coeff(m); for(int i = 1; i < n; i++) conv_coeff[i] = (*this)[i] * i; return online_convolution_exp(conv_coeff).pre(n); } P inv_fast() const { assert(((*this)[0]) != mint(0)); const int n = (int)this->size(); P res{mint(1) / (*this)[0]}; for(int d = 1; d < n; d <<= 1) { P f(2 * d), g(2 * d); for(int j = 0; j < std::min(n, 2 * d); j++) f[j] = (*this)[j]; for(int j = 0; j < d; j++) g[j] = res[j]; get_fft()(f); get_fft()(g); for(int j = 0; j < 2 * d; j++) f[j] *= g[j]; get_ifft()(f); for(int j = 0; j < d; j++) { f[j] = 0; f[j + d] = -f[j + d]; } get_fft()(f); for(int j = 0; j < 2 * d; j++) f[j] *= g[j]; get_ifft()(f); for(int j = 0; j < d; j++) f[j] = res[j]; res = f; } return res.pre(n); } P pow(int64_t k, int deg = -1) const { const int n = (int)this->size(); if(deg == -1) deg = n; for(int i = 0; i < n; i++) { if((*this)[i] != mint(0)) { mint rev = mint(1) / (*this)[i]; P ret = (((*this * rev) >> i).log() * k).exp() * ((*this)[i].pow(k)); if(i * k > deg) return P(deg, mint(0)); ret = (ret << (i * k)).pre(deg); if(ret.size() < deg) ret.resize(deg, mint(0)); return ret; } } return *this; } mint eval(mint x) const { mint r = 0, w = 1; for(auto &v : *this) { r += w * v; w *= x; } return r; } P pow_mod(int64_t n, P mod) const { P modinv = mod.rev().inv(); auto get_div = [&](P base) { if(base.size() < mod.size()) { base.clear(); return base; } int n = base.size() - mod.size() + 1; return (base.rev().pre(n) * modinv.pre(n)).pre(n).rev(n); }; P x(*this), ret{1}; while(n > 0) { if(n & 1) { ret *= x; ret -= get_div(ret) * mod; } x *= x; x -= get_div(x) * mod; n >>= 1; } return ret; } }; NumberTheoreticTransformFriendlyModInt ntt; using FPS = FormalPowerSeries; struct FPS_setup { FPS_setup() { auto mult = [&](const FPS::P &a, const FPS::P &b) { auto ret = ntt.multiply(a, b); return FPS::P(ret.begin(), ret.end()); }; FPS::set_mult(mult); FPS::set_fft([&](FPS::P &a) { ntt.ntt(a); }, [&](FPS::P &a) { ntt.intt(a); }); } } FPS_setup_; const int CombMAX = 1000010; mint fac[CombMAX + 1]; struct Combinationinit { Combinationinit() { fac[0] = fac[1] = 1; for(int i = 2; i <= CombMAX; i++) { fac[i] = fac[i - 1] * (mint)i; } } } Combinationinit_; int main() { int n; cin >> n; FPS f(n - 1); REP(i, n - 1) { f[i] = mint(i + 1) / fac[i]; } mint diviser = n; diviser = diviser.pow(n - 2); mint res = f.pow(n)[n - 2] * fac[n - 2] / diviser; cout << res << endl; return 0; }