#include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include using namespace std; template struct modint { private: unsigned int value; static constexpr int mod() {return m;} public: constexpr modint(const long long x = 0) noexcept { long long y = x; if(y < 0 || y >= mod()) { y %= mod(); if(y < 0) y += mod(); } value = (unsigned int)y; } constexpr unsigned int val() noexcept {return value;} constexpr modint &operator+=(const modint &other) noexcept { value += other.value; if(value >= mod()) value -= mod(); return *this; } constexpr modint &operator-=(const modint &other) noexcept { unsigned int x = value; if(x < other.value) x += mod(); x -= other.value; value = x; return *this; } constexpr modint &operator*=(const modint &other) noexcept { unsigned long long x = value; x *= other.value; value = (unsigned int) (x % mod()); return *this; } constexpr modint &operator/=(const modint &other) noexcept { return *this *= other.inverse(); } constexpr modint inverse() const noexcept { assert(value); long long a = value,b = mod(),x = 1,y = 0; while(b) { long long q = a/b; a -= q*b; swap(a,b); x -= q*y; swap(x,y); } return modint(x); } constexpr modint power(long long N) const noexcept { assert(N >= 0); modint p = *this,ret = 1; while(N) { if(N & 1) ret *= p; p *= p; N >>= 1; } return ret; } constexpr modint operator+() {return *this;} constexpr modint operator-() {return modint() - *this;} constexpr modint &operator++(int) noexcept {return *this += 1;} constexpr modint &operator--(int) noexcept {return *this -= 1;} friend modint operator+(const modint& lhs, const modint& rhs) {return modint(lhs) += rhs;} friend modint operator-(const modint& lhs, const modint& rhs) {return modint(lhs) -= rhs;} friend modint operator*(const modint& lhs, const modint& rhs) {return modint(lhs) *= rhs;} friend modint operator/(const modint& lhs, const modint& rhs) {return modint(lhs) /= rhs;} friend ostream &operator<<(ostream &os,const modint &x) {return os << x.value;} }; using mint = modint<998244353>; //using mint = modint<1000000007>; template struct SegmentTree { private: int siz; vector node; public: SegmentTree(int n = 0) noexcept { siz = 1; while(siz < n) siz <<= 1; node.assign(2*siz-1,e()); } void replace(int pos,T x) noexcept {func_update(pos,x,[](T u,T v){return u = v;});} void add(int pos,T x) noexcept {func_update(pos,x,[](T u,T v){return u+v;});} void func_update(int pos,T x) noexcept {func_update(pos,x,op);} void func_update(int pos,T x,T (*func)(T,T)) noexcept { assert(0 <= pos && pos < siz); pos += siz - 1; node[pos] = func(node[pos],x); while(pos) { pos = (pos-1)/2; node[pos] = op(node[2*pos+1],node[2*pos+2]); } } T operator [](int pos) noexcept { assert(0 <= pos && pos < siz); return node[pos+siz-1]; } T prod(int l,int r) noexcept { assert(0 <= l && l <= r && r <= siz); l += siz-1; r += siz-1; T Lval = e(); T Rval = e(); while(l < r) { if(!(l & 1)) Lval = op(Lval,node[l++]); if(!(r & 1)) Rval = op(node[--r],Rval); l >>= 1; r >>= 1; } return op(Lval,Rval); } T prod() noexcept {return node[0];} }; mint op(mint a,mint b) {return a+b;} mint e() {return 0;} int N,K; SegmentTree dp[2001]; void solve() { cin >> N >> K; for(int i = 0;i <= K;i++) dp[i] = SegmentTree(N+1); dp[0].replace(N,1); for(int i = N;i--;) { mint p = mint(N-i).inverse(); for(int j = 1;j <= K;j++) { mint ndp = dp[j-1].prod(i+1,N+1)*p; dp[j].replace(i,ndp); } } mint ans = 0; for(int i = 0;i <= K;i++) ans += dp[i][0]; cout << ans << endl; } int main() { ios::sync_with_stdio(false); cin.tie(nullptr); int tt = 1; //cin >> tt; while(tt--) solve(); }