#include <bits/stdc++.h>
using namespace std;
long long n, m, i, j, k, mm;
long long f[2001][3001][2] = {0};
int main() {
  cin >> n >> m;
  f[1][1][1] = 2;
  f[1][2][0] = 2;
  for (i = 2; i <= n; ++i) {
    if (2 * i < m)
      mm = 2 * i;
    else
      mm = m;
    for (j = 1; j <= mm; ++j) {
      f[i][j][1] = (f[i - 1][j][0] * 2 + f[i - 1][j][1] + f[i - 1][j - 1][1]) %
                   998244353;
      f[i][j][0] =
          (f[i - 1][j][0] + f[i - 1][j - 1][1] * 2 + f[i - 1][j - 2][0]) %
          998244353;
    }
  }
  cout << (f[n][m][0] + f[n][m][1]) % 998244353;
  return 0;
}
