#include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include using namespace std; template struct ModInt { int x; ModInt() : x(0) {} ModInt(long long y) : x(y >= 0 ? y % mod : (mod - (-y) % mod) % mod) {} ModInt &operator+=(const ModInt &p) { if ((x += p.x) >= mod) x -= mod; return *this; } ModInt &operator-=(const ModInt &p) { if ((x += mod - p.x) >= mod) x -= mod; return *this; } ModInt &operator*=(const ModInt &p) { x = (int)(1LL * x * p.x % mod); return *this; } ModInt &operator/=(const ModInt &p) { *this *= p.inverse(); return *this; } ModInt &operator^=(long long p) { // quick_pow here:3 ModInt res = 1; for (; p; p >>= 1) { if (p & 1) res *= *this; *this *= *this; } return *this = res; } ModInt operator-() const { return ModInt(-x); } ModInt operator+(const ModInt &p) const { return ModInt(*this) += p; } ModInt operator-(const ModInt &p) const { return ModInt(*this) -= p; } ModInt operator*(const ModInt &p) const { return ModInt(*this) *= p; } ModInt operator/(const ModInt &p) const { return ModInt(*this) /= p; } ModInt operator^(long long p) const { return ModInt(*this) ^= p; } bool operator==(const ModInt &p) const { return x == p.x; } bool operator!=(const ModInt &p) const { return x != p.x; } explicit operator int() const { return x; } // added by QCFium ModInt operator=(const int p) { x = p; return ModInt(*this); } // added by QCFium ModInt inverse() const { int a = x, b = mod, u = 1, v = 0, t; while (b > 0) { t = a / b; a -= t * b; std::swap(a, b); u -= t * v; std::swap(u, v); } return ModInt(u); } friend std::ostream &operator<<(std::ostream &os, const ModInt &p) { return os << p.x; } friend std::istream &operator>>(std::istream &is, ModInt &a) { long long x; is >> x; a = ModInt(x); return (is); } }; struct Mo { int n; std::vector> lr; explicit Mo(int n) : n(n) {} void add(int l, int r) { /* [l, r) */ lr.emplace_back(l, r); } template void build(const AL &add_left, const AR &add_right, const EL &erase_left, const ER &erase_right, const O &out) { int q = (int)lr.size(); int bs = n / std::min(n, sqrt(q)); std::vector ord(q); std::iota(std::begin(ord), std::end(ord), 0); std::sort(std::begin(ord), std::end(ord), [&](int a, int b) { int ablock = lr[a].first / bs, bblock = lr[b].first / bs; if (ablock != bblock) return ablock < bblock; return (ablock & 1) ? lr[a].second > lr[b].second : lr[a].second < lr[b].second; }); int l = 0, r = 0; for (auto idx : ord) { while (l > lr[idx].first) add_left(--l); while (r < lr[idx].second) add_right(r++); while (l < lr[idx].first) erase_left(l++); while (r > lr[idx].second) erase_right(--r); out(idx); } } template void build(const A &add, const E &erase, const O &out) { build(add, add, erase, erase, out); } }; void solve() { using mint = ModInt<998244353>; int n, k; std::cin >> n >> k; mint sum = k; for (int i = 0; i < n - 1; i++) { sum *= (mint)k; } // numberator -> n * k *( k - 1); mint num = (mint)n * k * (k - 1); std::cout << num / sum << '\n'; } int main() { std::ios::sync_with_stdio(false); std::cin.tie(nullptr); int t = 1; while (t--) solve(); return 0; }