#include <bits/stdc++.h>
const int N = 1010;
const int moder = 998244353;
int dp[N][N << 1][4];
int main() {
  int n, k;
  scanf("%d%d", &n, &k);
  dp[0][1][0] = dp[0][2][1] = dp[0][2][2] = dp[0][1][3] = 1;
  for (int i = 1; i < n; ++i) {
    for (int j = 0; j < N << 1; ++j) {
      for (int k = 0; k < 4; ++k) {
        if (!dp[i - 1][j][k]) continue;
        for (int u = 0; u < 4; ++u) {
          int add = __builtin_popcount(k ^ u);
          if ((u == 0 || u == 3) && add) {
            --add;
          }
          dp[i][j + add][u] += dp[i - 1][j][k];
          dp[i][j + add][u] -= dp[i][j + add][u] >= moder ? moder : 0;
        }
      }
    }
  }
  int ans = 0;
  for (int i = 0; i < 4; ++i) {
    ans += dp[n - 1][k][i];
    ans -= ans >= moder ? moder : 0;
  }
  printf("%d\n", ans);
  return 0;
}
