#include <bits/stdc++.h>
using namespace std;
const int maxn = 1e3 + 5;
const int mod = 998244353;
long long dp[maxn][maxn][4];
int main() {
  int n, m, k;
  cin >> n >> k;
  if (k == 2 * n) {
    cout << "2" << endl;
    return 0;
  } else if (k == 2 * n - 1 && n != 1) {
    cout << "0" << endl;
    return 0;
  }
  dp[1][2][1] = 1;
  dp[1][2][2] = 1;
  dp[1][1][0] = 1;
  dp[1][1][3] = 1;
  for (int i = 2; i <= n; i++) {
    for (int j = 1; j <= k; j++) {
      dp[i][j][0] = dp[i - 1][j - 1][3] + dp[i - 1][j][0] + dp[i - 1][j][1] +
                    dp[i - 1][j][2];
      dp[i][j][1] = dp[i - 1][j - 1][3] + dp[i - 1][j - 1][0] +
                    dp[i - 1][j][1] + (j >= 2 ? dp[i - 1][j - 2][2] : 0);
      dp[i][j][2] = dp[i - 1][j - 1][3] + dp[i - 1][j - 1][0] +
                    (j > 2 ? dp[i - 1][j - 2][1] : 0) + dp[i - 1][j][2];
      dp[i][j][3] = dp[i - 1][j][3] + dp[i - 1][j - 1][0] + dp[i - 1][j][1] +
                    dp[i - 1][j][2];
      for (m = 0; m < 4; m++) dp[i][j][m] %= 998244353;
    }
  }
  long long ans = 0;
  for (int i = 0; i <= 3; i++) {
    ans = (ans + dp[n][k][i]) % mod;
  }
  cout << ans << endl;
}
