#include <bits/stdc++.h>
using namespace std;
int n, k, dp[1010][2010][3];
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  cin >> n >> k;
  dp[1][1][1] = dp[1][2][2] = 2;
  for (int i = 2; i <= n; ++i) {
    dp[i][1][1] = dp[i][i << 1][2] = 2;
    for (int j = 1; j < 2 * i - 1; ++j) {
      dp[i][j][1] = ((long long)dp[i - 1][j - 1][1] + dp[i - 1][j][1] +
                     dp[i - 1][j][2] * 2) %
                    998244353;
      dp[i][j][2] = ((long long)dp[i - 1][j - 2][2] + dp[i - 1][j - 1][1] * 2 +
                     dp[i - 1][j][2]) %
                    998244353;
    }
  }
  cout << (dp[n][k][1] + dp[n][k][2]) % 998244353;
  return 0;
}
