#include <bits/stdc++.h>
using namespace std;
int n, k, ans;
long long dp[1001][1001 << 1][5];
const int MOD = 998244353;
int main() {
  cin >> n >> k;
  dp[1][1][1] = dp[1][1][2] = 1;
  dp[1][2][3] = dp[1][2][4] = 1;
  for (int i = 2; i <= n; i++) {
    dp[i][1][1] = dp[i][1][2] = 1;
    for (int j = 2; j <= k; j++) {
      (dp[i][j][1] += dp[i - 1][j][1] + dp[i - 1][j - 1][2] + dp[i - 1][j][3] +
                      dp[i - 1][j][4]) %= MOD;
      (dp[i][j][2] += dp[i - 1][j - 1][1] + dp[i - 1][j][2] + dp[i - 1][j][3] +
                      dp[i - 1][j][4]) %= MOD;
      (dp[i][j][3] += dp[i - 1][j - 1][1] + dp[i - 1][j - 1][1] +
                      dp[i - 1][j][3] + dp[i - 1][j - 2][4]) %= MOD;
      (dp[i][j][4] += dp[i - 1][j - 1][1] + dp[i - 1][j - 1][1] +
                      dp[i - 1][j - 2][3] + dp[i - 1][j][4]) %= MOD;
    }
  }
  ans = (dp[n][k][1] + dp[n][k][2] + dp[n][k][3] + dp[n][k][4]) % MOD;
  cout << ans;
  return 0;
}
