#include <bits/stdc++.h>
using namespace std;
long long n, k;
vector<long long> v;
long long dp[1001][2001][4];
long long rec(long long i, long long mask, long long comp) {
  if (i == n && comp == k)
    return 1;
  else if (i == n)
    return 0;
  else if (comp > k)
    return 0;
  if (dp[i][comp][mask] != -1) return dp[i][comp][mask];
  if (i == 0) {
    return dp[i][comp][mask] =
               (rec(i + 1, 0, comp + 1) + rec(i + 1, 1, comp + 2) +
                rec(i + 1, 2, comp + 2) + rec(i + 1, 3, comp + 1)) %
               998244353;
  }
  if (mask == 0) {
    return dp[i][comp][mask] =
               (rec(i + 1, 0, comp) + rec(i + 1, 3, comp + 1) +
                rec(i + 1, 1, comp + 1) + rec(i + 1, 2, comp + 1)) %
               998244353;
  } else if (mask == 1) {
    return dp[i][comp][mask] = (rec(i + 1, 0, comp) + rec(i + 1, 1, comp) +
                                rec(i + 1, 2, comp + 2) + rec(i + 1, 3, comp)) %
                               998244353;
  } else if (mask == 2) {
    return dp[i][comp][mask] = (rec(i + 1, 0, comp) + rec(i + 1, 1, comp + 2) +
                                rec(i + 1, 2, comp) + rec(i + 1, 3, comp)) %
                               998244353;
  } else if (mask == 3) {
    return dp[i][comp][mask] =
               (rec(i + 1, 0, comp + 1) + rec(i + 1, 1, comp + 1) +
                rec(i + 1, 2, comp + 1) + rec(i + 1, 3, comp)) %
               998244353;
  }
}
void solve() {
  memset(dp, -1, sizeof(dp));
  cin >> n >> k;
  cout << rec(0, 0, 0);
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  long long q = 1;
  while (q--) {
    v.clear();
    solve();
  }
}
