#include <bits/stdc++.h>
using namespace std;
long long dp[4][1005][2005];
const long long mod = 998244353;
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  int n, k;
  cin >> n >> k;
  dp[0][1][1] = dp[3][1][1] = 1;
  dp[1][1][2] = dp[2][1][2] = 1;
  for (int i = 2; i <= n; i++) {
    for (int j = 1; j <= k; j++) {
      dp[0][i][j] = (dp[0][i - 1][j] + dp[1][i - 1][j] + dp[2][i - 1][j] +
                     dp[3][i - 1][j - 1]) %
                    mod;
      dp[1][i][j] = (dp[0][i - 1][j - 1] + dp[1][i - 1][j] +
                     (j >= 2 ? dp[2][i - 1][j - 2] : 0) + dp[3][i - 1][j - 1]) %
                    mod;
      dp[2][i][j] = (dp[0][i - 1][j - 1] + (j >= 2 ? dp[1][i - 1][j - 2] : 0) +
                     dp[2][i - 1][j] + dp[3][i - 1][j - 1]) %
                    mod;
      dp[3][i][j] = (dp[0][i - 1][j - 1] + dp[1][i - 1][j] + dp[2][i - 1][j] +
                     dp[3][i - 1][j]) %
                    mod;
    }
  }
  int ans = 0;
  for (int i = 0; i < 4; i++) ans = (ans + dp[i][n][k]) % mod;
  cout << ans << endl;
}
