//Let's join Kaede Takagaki Fan Club !!
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <cmath>
#include <ctime>
#include <cassert>
#include <string>
#include <algorithm>
#include <vector>
#include <queue>
#include <stack>
#include <functional>
#include <iostream>
#include <map>
#include <set>
#include <unordered_map>
#include <unordered_set>
#include <cassert>
#include <iomanip>
#include <chrono>
#include <random>
#include <bitset>
#include <complex>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
#define int long long
//#define L __int128
typedef long long ll;
typedef pair<int,int> P;
typedef pair<int,P> P1;
typedef pair<P,P> P2;
#define pu push
#define pb push_back
#define eb emplace_back
#define mp make_pair
#define eps 1e-7
#define INF 1000000000
#define a first
#define b second
#define fi first
#define sc second
//#define rng(i,a,b) for(int i=(int)(a);i<(int)(b);i++)
#define rep(i,x) for(int i=0;i<x;i++)
#define repn(i,x) for(int i=1;i<=x;i++)
#define SORT(x) sort(x.begin(),x.end())
#define ERASE(x) x.erase(unique(x.begin(),x.end()),x.end())
#define POSL(x,v) (lower_bound(x.begin(),x.end(),v)-x.begin())
#define POSU(x,v) (upper_bound(x.begin(),x.end(),v)-x.begin())
#define all(x) x.begin(),x.end()
#define si(x) int(x.size())
#define pcnt(x) __builtin_popcountll(x)

#ifdef LOCAL
#define dmp(x) cerr<<__LINE__<<" "<<#x<<" "<<x<<endl
#else
#define dmp(x) void(0)
#endif
 
template<class t,class u> bool chmax(t&a,u b){if(a<b){a=b;return true;}else return false;}
template<class t,class u> bool chmin(t&a,u b){if(b<a){a=b;return true;}else return false;}
 
template<class t> using vc=vector<t>;
 
template<class t,class u>
ostream& operator<<(ostream& os,const pair<t,u>& p){
	return os<<"{"<<p.fi<<","<<p.sc<<"}";
}
 
template<class t> ostream& operator<<(ostream& os,const vc<t>& v){
	os<<"{";
	for(auto e:v)os<<e<<",";
	return os<<"}";
}
 
 //https://codeforces.com/blog/entry/62393
struct custom_hash {
	static uint64_t splitmix64(uint64_t x) {
		// http://xorshift.di.unimi.it/splitmix64.c
		x += 0x9e3779b97f4a7c15;
		x = (x ^ (x >> 30)) * 0xbf58476d1ce4e5b9;
		x = (x ^ (x >> 27)) * 0x94d049bb133111eb;
		return x ^ (x >> 31);
	}
 
	size_t operator()(uint64_t x) const {
		static const uint64_t FIXED_RANDOM = chrono::steady_clock::now().time_since_epoch().count();
		return splitmix64(x + FIXED_RANDOM);
	}
	//don't make x negative!
	size_t operator()(pair<int,int> x)const{
		return operator()(uint64_t(x.first)<<32|x.second);
	}
};
//unordered_set -> dtype, null_type
//unordered_map -> dtype(key), dtype(value)
using namespace __gnu_pbds;
template<class t,class u>
using hash_table=gp_hash_table<t,u,custom_hash>;

template<class T>
void g(T &a){
	cin >> a;
}
template<class T>
void o(const T &a,bool space=false){
	cout << a << (space?' ':'\n');
}
//ios::sync_with_stdio(false);
const ll mod = 998244353;
//const ll mod = 1000000007;
mt19937_64 mt(chrono::steady_clock::now().time_since_epoch().count());
template<class T>
void add(T&a,T b){
	a+=b;
	if(a >= mod) a-=mod;
}
ll modpow(ll a,ll n){
    ll cur = a,ret = 1;
    while(n){
        if(n%2 == 1) ret = ret*cur%mod;
        cur = cur*cur%mod;
        n /= 2;
    }
    return ret;
}

#define _sz 400005
ll F[_sz],R[_sz];
void make(){
	F[0] = 1;
	for(int i=1;i<_sz;i++) F[i] = F[i-1]*i%mod;
	R[_sz-1] = modpow(F[_sz-1], mod-2);
	for(int i=_sz-2;i>=0;i--) R[i] = R[i+1] * (i+1) % mod;
}
ll C(int a,int b){
	if(b < 0 || a < b) return 0;
	return F[a]*R[b]%mod*R[a-b]%mod;
}
const int md = 998244353;
 
inline void add(int &a, int b) {
  a += b;
  if (a >= md) a -= md;
}
 
inline void sub(int &a, int b) {
  a -= b;
  if (a < 0) a += md;
}
 
inline int mul(int a, int b) {
  return (int) ((long long) a * b % md);
}
 
inline int power(int a, long long b) {
  int res = 1;
  while (b > 0) {
    if (b & 1) {
      res = mul(res, a);
    }
    a = mul(a, a);
    b >>= 1;
  }
  return res;
}
 
inline int inv(int a) {
  a %= md;
  if (a < 0) a += md;
  int b = md, u = 0, v = 1;
  while (a) {
    int t = b / a;
    b -= t * a; swap(a, b);
    u -= t * v; swap(u, v);
  }
  assert(b == 1);
  if (u < 0) u += md;
  return u;
}
 
namespace ntt {
  int base = 1;
  vector<int> roots = {0, 1};
  vector<int> rev = {0, 1};
  int max_base = -1;
  int root = -1;
 
  void init() {
  	base = 1;
  	roots = {0,1};
  	rev = {0,1};
  	max_base = -1;
  	root = -1;
    int tmp = md - 1;
    max_base = 0;
    while (tmp % 2 == 0) {
      tmp /= 2;
      max_base++;
    }
    root = 2;
    while (true) {
      if (power(root, 1 << max_base) == 1) {
        if (power(root, 1 << (max_base - 1)) != 1) {
          break;
        }
      }
      root++;
    }
  }
 
  void ensure_base(int nbase) {
    if (max_base == -1) {
      init();
    }
    if (nbase <= base) {
      return;
    }
    assert(nbase <= max_base);
    rev.resize(1 << nbase);
    for (int i = 0; i < (1 << nbase); i++) {
      rev[i] = (rev[i >> 1] >> 1) + ((i & 1) << (nbase - 1));
    }
    roots.resize(1 << nbase);
    while (base < nbase) {
      int z = power(root, 1 << (max_base - 1 - base));
      for (int i = 1 << (base - 1); i < (1 << base); i++) {
        roots[i << 1] = roots[i];
        roots[(i << 1) + 1] = mul(roots[i], z);
      }
      base++;
    }
  }
 
  void fft(vector<int> &a) {
    int n = a.size();
    assert((n & (n - 1)) == 0);
    int zeros = __builtin_ctz(n);
    ensure_base(zeros);
    int shift = base - zeros;
    for (int i = 0; i < n; i++) {
      if (i < (rev[i] >> shift)) {
        swap(a[i], a[rev[i] >> shift]);
      }
    }
    for (int k = 1; k < n; k <<= 1) {
      for (int i = 0; i < n; i += 2 * k) {
        for (int j = 0; j < k; j++) {
          int x = a[i + j];
          int y = mul(a[i + j + k], roots[j + k]);
          a[i + j] = x + y - md;
          if (a[i + j] < 0) a[i + j] += md;
          a[i + j + k] = x - y + md;
          if (a[i + j + k] >= md) a[i + j + k] -= md;
        }
      }
    }
  }
 
  vector<int> multiply(vector<int> a, vector<int> b, int eq = 0) {
    int need = a.size() + b.size() - 1;
    int nbase = 0;
    while ((1 << nbase) < need) nbase++;
    ensure_base(nbase);
    int sz = 1 << nbase;
    a.resize(sz);
    b.resize(sz);
    fft(a);
    if (eq) b = a; else fft(b);
    int inv_sz = inv(sz);
    for (int i = 0; i < sz; i++) {
      a[i] = mul(mul(a[i], b[i]), inv_sz);
    }
    reverse(a.begin() + 1, a.end());
    fft(a);
    a.resize(need);
    return a;
  }
 
  vector<int> square(vector<int> a) {
    return multiply(a, a, 1);
  }
};


namespace power_series_master {
    //x^iの係数をvecc[i]にもつものとする
    //各々の処理はmod x^Mをサポートするものとする
    
    //add,sub,diff,intg,mul_int,mul,inv,sqrt,log,exp
    //add subでミスってたら流石に引退
    //diff,intgも流石に大丈夫だと思うけど、diffに定数を噛ませて0を返す仕様で変なハマり方をしないか心配
    //一番怖いのはlogで、手元でexpと組み合わせてテストしたら大丈夫そうだったけど、GP peterhof H でverifyしたいよね
    //mod は998244353固定なので、他の素数だった場合はmulをarbitrary_mod_convに変えないといけない
    
    //verify list
    
    //mul_int,sub,sqrt,inv... CF 438E
    //exp... yosupo judge
    #define vi vector<int>
    vi init(vi a, int x){
    	a.resize(x,0);
    	return a;
    }
    vi add(vi a, vi b,int M=-1){
        if(a.size() < b.size()) swap(a,b);
        for(int i=0;i<b.size();i++){
            a[i]+=b[i];
            if(a[i] < 0) a[i] += mod;
            if(a[i] >= mod) a[i] -= mod;
        }
        if(M >= 0 && a.size() > M) a.resize(M);
        return a;
    }
    vi sub(vi a, vi b,int M=-1){
        if(a.size() < b.size()) a.resize(b.size(),0);
        for(int i=0;i<b.size();i++){
            a[i]-=b[i];
            if(a[i] < 0) a[i] += mod;
            if(a[i] >= mod) a[i] -= mod;
        }
        if(M >= 0 && a.size() > M) a.resize(M);
        return a;
    }
    //微分
    vi diff(vi a,int M=-1){
    	reverse(a.begin(),a.end());
    	a.pop_back();
    	reverse(a.begin(),a.end());
    	for(int i=0;i<a.size();i++) a[i] = 1LL*a[i]*(i+1)%mod;
    	if(M >= 0 && a.size() > M) a.resize(M);
    	if(a.empty()) a.pb(0);
    	return a;
    }
    //積分、定数項は指定可能
    vi intg(vi a,int coef=0,int M=-1){
    	reverse(a.begin(),a.end());
    	a.push_back(coef);
    	reverse(a.begin(),a.end());
    	for(int i=1;i<a.size();i++) a[i] = 1LL*a[i]*modpow(i,mod-2)%mod;
    	if(M >= 0 && a.size() > M) a.resize(M);
    	return a;
    }
    vi mul_int(vi a,int x,int M=-1){
        for(int i=0;i<a.size();i++){
            ll A = 1LL*a[i]*x%mod;
            if(A < 0) A += mod;
            a[i] = A;
        }
        if(M >= 0 && a.size() > M) a.resize(M);
        return a;
    }
    vi mul(vi a,vi b,int M=-1){
        //modが99...のときはnttできる
        //任意modの場合は、適当に区切ってもいいしgarnerしてもいいし任せます
        ntt::init();
		a = ntt::multiply(a,b);
		if(M >= 0 && a.size() > M) a.resize(M);
        return a;
    }
    //vecで表される多項式の-1乗、x^(M-1)の項までを求めてM長のvectorを返す
    //ただし、vec[0] = 0の場合は無理
    //r1(z)f(z) = x*? + 1
    //rn(z)f(z) = x^n*? + 1とする
    //r(2n)(z) = 2*rn(z)-rn(z)^2f(z)とすればOK!
    vi inv(vi a,int M){
        if(a.empty() || a[0] == 0) return vi();
        //1の場合をやっておく
        vi r[30];
        r[0].pb(modpow(a[0],mod-2));
        int cur = 1;
        int nxt = 1;
        vi vec3;
        while(cur < M){
        	int nw = min(cur*2,(int)(a.size()));
        	int sz = vec3.size();
        	vec3.resize(nw,0);
        	for(int t=sz;t<nw;t++){
        		vec3[t] = a[t];
        	}
            r[nxt] = sub(mul_int(r[nxt-1],2),mul(mul(r[nxt-1],r[nxt-1]),vec3));
            r[nxt].resize(r[nxt-1].size()*2);
            nxt++;
            cur *= 2;
        }
        assert(r[nxt-1].size() >= M);
        r[nxt-1].resize(M);
        assert(r[nxt-1].size() == M);
        return r[nxt-1];
    }
    //vecで表される多項式の平方根、x^(M-1)の項までを求めてM長のvectorを返す
    //ただし、vec[0] = 0の場合は無理
    //整数の平方根求めるのかったるいのでそれはまた後日
    //s1(z)^2 = f(z) (mod z)
    //sn(z)^2 = f(z) (mod z^n) とする
    //s(2n)(z) = 1/2 * (sn(z)+f(z)*sn(z)^-1)
    vi sqrt(vi a,int M){
        if(a.empty() || a[0] == 0) return vi();
        //1の場合をやっておく
        vi s[30];
        //今日はvec[0] = 1のことしか考えません
        s[0].pb(1);
        assert(1LL*s[0][0]*s[0][0]%mod == a[0]);
        int cur = 1;
        int nxt = 1;
        vi vec3;
        while(cur < M){
            int nw = min(cur*2,(int)(a.size()));
        	int sz = vec3.size();
        	vec3.resize(nw,0);
        	for(int t=sz;t<nw;t++){
        		vec3[t] = a[t];
        	}
            s[nxt] = add(s[nxt-1],mul(vec3,inv(s[nxt-1],cur*2)));
            s[nxt] = mul_int(s[nxt],modpow(2,mod-2));
            s[nxt].resize(cur*2);
            nxt++;
            cur *= 2;
        }
        s[nxt-1].resize(M);
        assert(s[nxt-1].size() == M);
        return s[nxt-1];
    }
    //vecで表される多項式のlog()、x^(M-1)の項までを求めてM長のvectorを返す
    //ただし、vec[0] = 0の場合は無理
    //log(f(x)) = intg(f'(x)/f(x)) = intg(mul(diff(f(x),need+1),inv(f(x),need+1),need+1))
    //積分定数は0固定なので、vec[0]!=1のものを噛ませた場合は壊れる
    vi log(vi a,int M){
        if(a.empty() || a[0] == 0) return vi();
        vi x = diff(a,M);
        vi y = inv(a,M);
        vi z = mul(x,y,M);
        return intg(z,0,M);
    }
    //vecで表される多項式のexp()、x^(M-1)の項までを求めてM長のvectorを返す
    //ただし、vec[0] != 0の場合は無理
    //exp(a)の定数項は必ず1なので、定数項!=1の多項式のlogを噛ませた場合は壊れる
    //http://www.csd.uwo.ca/~eschost/publications/BoSc09-final.pdf
    vi exp(vi a,int M){
        if(a.empty() || a[0] != 0) return vi();
        vi f={1},g={1},q,aa;
        int m = 1;
        vi h = diff(a);
        while(m<=M){
			g = sub(mul_int(g,2,m),mul(mul(f,g,m),g,m),m);
			while(aa.size() < 2*m){
			    if(aa.size() >= a.size()) aa.pb(0);
			    else aa.pb(a[aa.size()]);
			}
			if(m>1){
				vi w = add(q,mul(g,sub(diff(f,2*m-1),mul(f,q,2*m-1),2*m-1),2*m-1),2*m-1);
				f = add(f,mul(f,sub(aa,intg(w,0,2*m),2*m),2*m),2*m);
			}
			else{
				vi w = mul(g,diff(f,2*m-1),2*m-1);
				f = add(f,mul(f,sub(aa,intg(w,0,2*m),2*m),2*m),2*m);
			}
			m*=2;
			while(q.size() < m-1){
				if(q.size() >= h.size()) q.pb(0);
				else q.pb(h[q.size()]);
			}
		}
		f.resize(M);
		assert(f.size() == M);
		return f;
    }
};
int n, k; 
//o(ans?"Yes":"No");
void solve(){
	cin >> n >> k;
	make();
	int ans = C(2*n, n);
	if(k == 1);
	else if(k == 2) ans = (ans+mod-2) % mod;
	else{
		//k-3, k-2, k-1
		vc<int>pl[3];
		rep(i, 3){
			pl[i].resize(k, 0);
			for(int x=0;x<k;x++){
				int a = C(k-2+i-x, x);
				if(a == 0) break;
				pl[i][x] = (x%2==1?mod-a:a)%mod;
			}
		}
		auto oo = power_series_master::inv(pl[1],n+2);
		auto tt = power_series_master::inv(pl[2],n+2);
		pl[0] = power_series_master::mul(pl[0], oo);
		pl[1] = power_series_master::mul(pl[1], tt);
		for(int i=1;i<=n;i++){
			ans -= pl[0][i-1]*2*i%mod*pl[1][n-i]%mod;
		}
		ans = (ans%mod+mod)%mod;
	}
	o(ans);
}
signed main(){
	cin.tie(0);
	ios::sync_with_stdio(0);
	cout<<fixed<<setprecision(20);
	int t; t = 1; //cin >> t;
	while(t--) solve();
}