#if __INCLUDE_LEVEL__ == 0 #include __BASE_FILE__ namespace { using Fp = atcoder::modint998244353; void solve() { int n, k; scan(n, k); vector p(n + 1); p[0] = 1; Fp inv_n = Fp(n).inv(); for (int _ = k; _--;) { vector np(n + 1); for (int i : rep(n + 1)) { if (i) { np[i - 1] += p[i] * i * inv_n; } if (i < n) { np[i + 1] += p[i] * (n - i) * inv_n; } } p = move(np); } Fp ans = n; for (int i : rep(n + 1)) { ans += (k - i) / 2 * p[i]; } print(ans); } } // namespace int main() { ios::sync_with_stdio(false); cin.tie(nullptr); solve(); } #else // __INCLUDE_LEVEL__ #include using namespace std; #include namespace std { template istream& operator>>(istream& is, pair& p) { return is >> p.first >> p.second; } template istream& operator>>(istream& is, tuple& t) { return apply([&is](auto&... xs) -> istream& { return (is >> ... >> xs); }, t); } template >* = nullptr> auto operator>>(istream& is, R&& r) -> decltype(is >> *begin(r)) { for (auto&& e : r) { is >> e; } return is; } template ostream& operator<<(ostream& os, const pair& p) { return os << p.first << ' ' << p.second; } template ostream& operator<<(ostream& os, const tuple& t) { auto f = [&os](const auto&... xs) -> ostream& { [[maybe_unused]] auto sep = ""; ((os << exchange(sep, " ") << xs), ...); return os; }; return apply(f, t); } template >* = nullptr> auto operator<<(ostream& os, R&& r) -> decltype(os << *begin(r)) { auto sep = ""; for (auto&& e : r) { os << exchange(sep, " ") << e; } return os; } } // namespace std namespace atcoder { template * = nullptr> istream& operator>>(istream& is, T& x) { int v; is >> v; x = T::raw(v); return is; } template * = nullptr> ostream& operator<<(ostream& os, const T& x) { return os << x.val(); } } // namespace atcoder template void scan(Ts&&... xs) { (cin >> ... >> xs); } template void print(Ts&&... xs) { cout << tie(xs...) << '\n'; } inline auto rep(int l, int r) { return views::iota(min(l, r), r); } inline auto rep(int n) { return rep(0, n); } inline auto rep1(int l, int r) { return rep(l, r + 1); } inline auto rep1(int n) { return rep(1, n + 1); } inline auto per(int l, int r) { return rep(l, r) | views::reverse; } inline auto per(int n) { return per(0, n); } inline auto per1(int l, int r) { return per(l, r + 1); } inline auto per1(int n) { return per(1, n + 1); } inline auto len = ranges::ssize; #endif // __INCLUDE_LEVEL__