#include <bits/stdc++.h>
using namespace std;
const int MOD = 998244353;
long long int memo[1005][2005][4];
int n, k;
void solve() {
  for (int i = 2; i <= n; i++) {
    for (int j = 1; j <= i * 2; j++) {
      memo[i][j][0] = (memo[i - 1][j][0] + memo[i - 1][j][1] +
                       memo[i - 1][j][2] + memo[i - 1][j - 1][3]) %
                      MOD;
      memo[i][j][1] = (memo[i - 1][j - 1][0] + memo[i - 1][j][1] +
                       memo[i - 1][j - 2][2] + memo[i - 1][j - 1][3]) %
                      MOD;
      memo[i][j][2] = (memo[i - 1][j - 1][0] + memo[i - 1][j - 2][1] +
                       memo[i - 1][j][2] + memo[i - 1][j - 1][3]) %
                      MOD;
      memo[i][j][3] = (memo[i - 1][j - 1][0] + memo[i - 1][j][1] +
                       memo[i - 1][j][2] + memo[i - 1][j][3]) %
                      MOD;
    }
  }
}
int main() {
  cin >> n >> k;
  memo[1][1][0] = 1;
  memo[1][2][1] = 1;
  memo[1][2][2] = 1;
  memo[1][1][3] = 1;
  solve();
  printf("%lld",
         (memo[n][k][0] + memo[n][k][1] + memo[n][k][2] + memo[n][k][3]) % MOD);
}
