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

using mint = modint998244353;

int main() {
    int N, K;
    cin >> N >> K;

    vector<vector<mint>> dp(K + 1, vector<mint>(2));
    dp[0][0] = 1;

    for (int t = 0; t < N * 2; ++t) {
        vector<vector<mint>> ndp(K + 1, vector<mint>(2));
        for (int i = 0; i <= K; ++i) {
            for (int j = 0; j < 2; ++j) {
                if (i >= 1) {
                    ndp[i - 1][j] += dp[i][j];
                }
                if (i + 1 <= K) {
                    ndp[i + 1][j || (i + 1 == K)] += dp[i][j];
                }
            }
        }
        dp = ndp;
    }

    cout << dp[0][1].val() << endl;
    return 0;
}