//#define //_GLIBCXX_DEBUG
#include <bits/stdc++.h>
#include <deque>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
using ll = long long;
using ull = unsigned long long;
using vll=vector<ll>;
using vvll=vector<vector<ll>>;
using Graph=vvll;
using Edgegraph=vector<vector<pair<ll,ll>>>;
using vch=vector<char>;
using vvch=vector<vector<char>>;
using P=pair<ll,ll>;
using vP=vector<P>;
using tup=tuple<ll,ll,ll>;
using vbl=vector<bool>;
using vvbl=vector<vbl>;
using vs=vector<string>;
using vvs=vector<vs>;
using vd=vector<double>;
using vvd=vector<vd>;
using mint = atcoder::modint998244353;
const int infint = 1073741823;
const ll inf = 1LL << 60;
template <class T> inline bool chmax(T& a,T b){if (a<b){a=b;return 1;}return 0;}
template <class T> inline bool chmin(T& a,T b){if (a>b){a=b;return 1;}return 0;}
#define rep(i,x,lim) for(ll i = (x);i < (ll)(lim);i++)
#define rep2(j,x,lim) for(int j = (x);j < (int)(lim);j++)
const ll big=(1e+9)+7;
const ll big2=998244353;

ll dx[8]={1,-1,0,0,1,1,-1,-1};
ll dy[8]={0,0,1,-1,1,-1,1,-1};

int modpow(ll x,ll n,ll m){
    if(n==0) return 1%m;
    x=((x%m)+m)%m;
    if(n%2==0){
        ll r=modpow(x,n/2,m);
        return r*r%m;
    }
    else{
        ll r=modpow(x,n/2,m);
        return r*r%m*x%m;
    }
}
//pは素数でなければならない。
int revmod(ll x,ll p){return modpow(x,p-2,p);}
//99 のRを高速に求める
int modp(ll p,ll q){
    ll gc=gcd(p,q);
    p/=gc;q/=gc;
    ll rev=revmod(p,big2);
    return (rev*q)%big2;
}
//nCrを求める modbig2
int nCr(ll n,ll r){
     ll ans=1;
    rep(i,1,n+1) ans=(ans*i)%big2;
    rep(i,1,r+1) ans=(ans*modpow(i,big2-2,big2))%big2;
    rep(i,1,n-r+1) ans=(ans*modpow(i,big2-2,big2))%big2;
    return ans;
}
ll op(ll a,ll b){return max(a,b);}
ll opmin(ll a,ll b){return min(a,b);}
ll e(){return 0;}

int main(){
    ll N,K;
    cin >> N >> K;
    vvll dp(2*N+1,vll(K+1));
    dp[0][0]=1;
    rep(i,1,2*N+1){
        rep(j,0,K+1){
            if(j-1>=0)dp[i][j]=(dp[i][j]+dp[i-1][j-1])%big2;
            if(j+1<=K)dp[i][j]=(dp[i][j]+dp[i-1][j+1])%big2;
        }
    }
    vvll dp2(2*N+1,vll(K));
    dp2[0][0]=1;
    rep(i,1,2*N+1){
        rep(j,0,K){
            if(j-1>=0)dp2[i][j]=(dp2[i][j]+dp2[i-1][j-1])%big2;
            if(j+1<=K)dp2[i][j]=(dp2[i][j]+dp2[i-1][j+1])%big2;
        }
    }
    cout << dp[2*N][0]-dp2[2*N][0];
}