#include<bits/stdc++.h>
#include<atcoder/all>
using namespace std;
using namespace atcoder;
typedef long long int ll;
typedef long double ld;
typedef vector<ll> vi;
typedef vector<vi> vvi;
typedef vector<vvi> vvvi;
typedef vector<vvvi> vvvvi;
typedef vector<bool> vb;
typedef vector<vb> vvb;
typedef vector<vvb> vvvb;
typedef vector<vvvb> vvvvb;
typedef pair<ll,ll> pi;
typedef pair<ll,pi> ppi;
typedef pair<ll,ppi> pppi;
typedef pair<ll,pppi> ppppi;
#define FOR(i,l,r) for(ll i=l;i<r;i++)
#define REP(i,n) FOR(i,0,n)
#define RFOR(i,l,r) for(ll i=r-1;i>=l;i--)
#define RREP(i,n) RFOR(i,0,n)
#define ALL(x) x.begin(),x.end()
#define F first
#define S second
#define BS(A,x) binary_search(ALL(A),x)
#define LB(A,x) (ll)(lower_bound(ALL(A),x)-A.begin())
#define UB(A,x) (ll)(upper_bound(ALL(A),x)-A.begin())
#define COU(A,x) (UB(A,x)-LB(A,x))
#define sz(c) ((ll)(c).size())
/*
#include<boost/multiprecision/cpp_int.hpp>
namespace mp=boost::multiprecision;
using Bint=mp::cpp_int;
*/
template<typename T>using min_priority_queue=priority_queue<T,vector<T>,greater<T>>;
template<typename T1,typename T2>ostream&operator<<(ostream&os,pair<T1,T2>p){os<<p.F<<" "<<p.S;return os;}
template<typename T1,typename T2>istream&operator>>(istream&is,pair<T1,T2>&p){is>>p.F>>p.S;return is;}
template<typename T>ostream&operator<<(ostream&os,vector<T>v){REP(i,sz(v))os<<v[i]<<(i+1!=sz(v)?" ":"");return os;}
template<typename T>istream&operator>>(istream&is,vector<T>&v){for(T&in:v)is>>in;return is;}
template<class T>bool chmax(T&a,T b){if(a<b){a=b;return 1;}return 0;}
template<class T>bool chmin(T&a,T b){if(b<a){a=b;return 1;}return 0;}
ld dist(ld x1,ld y1,ld x2,ld y2){return sqrtl((x1-x2)*(x1-x2)+(y1-y2)*(y1-y2));}
vi fast_mod_convolution(vi&a,vi&b,ll mod){
  const ll m1=167772161,m2=469762049,m3=1224736769;
  const ll m1_inv_m2=inv_mod(m1,m2);
  const ll m12_inv_m3=inv_mod(m1*m2,m3);
  const ll m12_mod=m1*m2%mod;
  auto x=convolution<m1>(a,b);
  auto y=convolution<m2>(a,b);
  auto z=convolution<m3>(a,b);
  vector<ll>ret(sz(a)+sz(b)-1);
  REP(i,sz(ret)){
    ll v1=(y[i]-x[i])*m1_inv_m2%m2;if(v1<0)v1+=m2;
    ll v2=(z[i]-(x[i]+m1*v1)%m3)*m12_inv_m3%m3;if(v2<0)v2+=m3;
  	ret[i]=(x[i]+m1*v1+m12_mod*v2)%mod;
  }
  return ret;
}
const ld EPS=1e-8;
//*
using mint=modint998244353;
const ll mod=998244353;
//*/
/*
using mint=modint1000000007;
const ll mod=1000000007;
//*/
//using mint=modint;
//*
typedef vector<mint> vm;
typedef vector<vm> vvm;
typedef vector<vvm> vvvm;
typedef vector<vvvm> vvvvm;
ostream&operator<<(ostream&os,mint a){os<<a.val();return os;}
istream&operator>>(istream&is,mint&a){int x;is>>x;a=mint(x);return is;}
//*/
template<typename T>
vector<vector<T>>f(vector<vector<T>>&a,vector<vector<T>>&b){
  vector<vector<T>>c(3,vector<T>(3,T(a[0][0].size())));
  REP(i,3)REP(j,3)REP(k,3){
  	auto d=convolution(a[i][k],b[k][j]);
  	REP(l,a[0][0].size())c[i][j][l]+=d[l];
 }
  return c;
}
int main(){
  ll N,H;cin>>N>>H;
  vvvm A(3,vvm(3,vm(N+10)));
  A[0][1][0]=A[1][2][0]=1;
  A[2][0][2]=-inv_mod(9,mod);
  A[2][1][1]=-inv_mod(6,mod);
  A[2][1][2]=inv_mod(9,mod);
  A[2][2][0]=inv_mod(2,mod);
  A[2][2][1]=2*inv_mod(3,mod);
  vvvvm B(20,vvvm(3,vvm(3,vm(N+10))));;
  B[0]=A;
  FOR(i,1,20)B[i]=f(B[i-1],B[i-1]);
  vvvm C(3,vvm(3,vm(N+10)));
  C[0][0][0]=C[1][1][0]=C[2][2][0]=1;
  REP(i,20)if(((N-1)>>i)%2)C=f(C,B[i]);
  vm ans(N+10);
  REP(i,N+5){
  	ans[i+2]-=10*C[0][2][i];
  	ans[i+2]+=6*C[1][2][i];
  	ans[i+1]-=21*C[1][2][i];
  	ans[i]+=C[2][2][i]*36;
  	ans[i+1]+=C[2][2][i]*54;
  }
  REP(i,N+10)ans[i]/=90;
  mint sum=0;
  FOR(i,H,N+1)sum+=ans[i];
  cout<<sum<<endl;
  return 0;
}