#include <bits/stdc++.h>
using namespace std;
const long long mod = 998244353;
long long dp[1001][2001][4];
long long solve(long long n, long long k, long long i) {
  if (dp[n][k][i] != -1) {
    return dp[n][k][i];
  }
  if (k < 1 || k > 2 * n) return 0;
  if (i == 0) {
    dp[n][k][i] = solve(n - 1, k, 0) + solve(n - 1, k - 1, 1) +
                  solve(n - 1, k - 1, 2) + solve(n - 1, k - 2, 3);
  } else if (i == 1) {
    dp[n][k][i] = solve(n - 1, k, 0) + solve(n - 1, k, 1) +
                  solve(n - 1, k - 1, 2) + solve(n - 1, k, 3);
  } else if (i == 2) {
    dp[n][k][i] = solve(n - 1, k, 0) + solve(n - 1, k - 1, 1) +
                  solve(n - 1, k, 2) + solve(n - 1, k, 3);
  } else {
    dp[n][k][i] = solve(n - 1, k - 2, 0) + solve(n - 1, k - 1, 1) +
                  solve(n - 1, k - 1, 2) + solve(n - 1, k, 3);
  }
  dp[n][k][i] %= mod;
  return dp[n][k][i];
}
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  memset(dp, -1, sizeof dp);
  long long n, k;
  cin >> n >> k;
  dp[1][1][0] = dp[1][1][3] = 0;
  dp[1][1][1] = dp[1][1][2] = 1;
  dp[1][2][0] = dp[1][2][3] = 1;
  dp[1][2][1] = dp[1][2][2] = 0;
  cout << (solve(n, k, 0) + solve(n, k, 1) + solve(n, k, 2) + solve(n, k, 3)) %
              mod
       << endl;
}
