// Original Python code:
// import sys
// sys.setrecursionlimit(10**4)
// MOD = 998244353
// N,K = list(map(int,input().split()))
//
// def f(n,now_depth,MAX_DEPTH):
//     if(n == 2*N):return 1 if now_depth == 0 else 0
//     if(memo[n][now_depth] != -1):return memo[n][now_depth]
//     ret = 0
//     # (
//     if(now_depth < MAX_DEPTH):ret += f(n+1,now_depth+1,MAX_DEPTH)
//     # )
//     if(now_depth >= 1):ret += f(n+1,now_depth-1,MAX_DEPTH)
//
//     memo[n][now_depth] = ret % MOD
//     return ret % MOD
//
// memo = [[-1 for _ in range(K+1)] for _ in range(2*N)]
// ans = f(0,0,K)
// memo = [[-1 for _ in range(K+1)] for _ in range(2*N)]
// ans -= f(0,0,K-1)
// print(ans)

#include <bits/stdc++.h>
using namespace std;

const int MOD = 998244353;
int N, K;
vector<vector<long long>> memo;

// f(n, now_depth, MAX_DEPTH)
long long f(int n, int now_depth, int MAX_DEPTH) {
    if (n == 2 * N) {
        return (now_depth == 0) ? 1 : 0;
    }
    if (memo[n][now_depth] != -1) {
        return memo[n][now_depth];
    }
    long long ret = 0;
    // "("
    if (now_depth < MAX_DEPTH) {
        ret += f(n + 1, now_depth + 1, MAX_DEPTH);
    }
    // ")"
    if (now_depth >= 1) {
        ret += f(n + 1, now_depth - 1, MAX_DEPTH);
    }
    return memo[n][now_depth] = (ret % MOD);
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    cin >> N >> K;

    // First count with MAX_DEPTH = K
    memo.assign(2 * N, vector<long long>(K + 1, -1));
    long long ans = f(0, 0, K);

    // Reset memo and subtract count with MAX_DEPTH = K-1
    memo.assign(2 * N, vector<long long>(K + 1, -1));
    ans = (ans - f(0, 0, K - 1) + MOD) % MOD;

    cout << ans << "\n";
    return 0;
}