#include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>
#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
using ll = long long;
using mint = modint998244353;
using vi = vector<int>;
using vvi = vector<vi>;
using vvvi = vector<vvi>;
using vll = vector<ll>;
using vvll = vector<vll>;
using vvvll = vector<vvll>;
using vmi = vector<mint>;
using vvmi = vector<vmi>;
using vvvmi = vector<vvmi>;
#define all(a) (a).begin(), (a).end()
#define rep2(i, m, n) for (int i = (m); i < (n); ++i)
#define rep(i, n) rep2(i, 0, n)
#define drep2(i, m, n) for (int i = (m)-1; i >= (n); --i)
#define drep(i, n) drep2(i, n, 0)


int main(){

    int n, k; cin >> n >> k;
    if(k == 1){
        cout << 1 << endl;
        return 0;
    }
    vvmi dp1(2, vmi(k+1, mint(0)));
    dp1[0][1] = mint(1);
    rep2(i, 1, 2*n){
        int a = i%2;
        rep(j, k+1){
            if(j == 0){
                dp1[a][j] = dp1[1-a][j+1];
            }else if(j == k){
                dp1[a][j] = dp1[1-a][j-1];
            }else{
                dp1[a][j] = dp1[1-a][j-1]+dp1[1-a][j+1];
            }
        }
    }

    vvmi dp2(2, vmi(k, mint(0)));
    dp2[0][1] = mint(1);
    rep2(i, 1, 2*n){
        int a = i%2;
        rep(j, k){
            if(j == 0){
                dp2[a][j] = dp2[1-a][j+1];
            }else if(j == k-1){
                dp2[a][j] = dp2[1-a][j-1];
            }else{
                dp2[a][j] = dp2[1-a][j-1]+dp2[1-a][j+1];
            }
        }
    }

    cout << (dp1[1][0]-dp2[1][0]).val() << endl;
    return 0;
}