#include <bits/stdc++.h>
using namespace std;
long long dp[1001][2 * 1001][2];
long long MOD = 998244353;
int main() {
  ios_base::sync_with_stdio(false);
  int n, k;
  cin >> n >> k;
  dp[1][1][0] = 2;
  dp[1][2][0] = 0;
  dp[1][1][1] = 0;
  dp[1][2][1] = 2;
  for (int i = 2; i <= n; ++i) {
    for (int j = 1; j <= min(2 * n, k); ++j) {
      dp[i][j][0] = dp[i - 1][j][0] + dp[i - 1][j - 1][0] + dp[i - 1][j][1] * 2;
      dp[i][j][0] %= MOD;
      dp[i][j][1] =
          dp[i - 1][j][1] + dp[i - 1][j - 2][1] + dp[i - 1][j - 1][0] * 2;
      dp[i][j][1] %= MOD;
    }
  }
  cout << (dp[n][k][0] + dp[n][k][1]) % MOD << "\n";
}
