#include <bits/stdc++.h>
int dp[1003][2006][4] = {0};
int main() {
  int n, lm;
  scanf("%d %d", &n, &lm);
  dp[1][1][0] = 1;
  dp[1][2][2] = 1;
  dp[1][2][1] = 1;
  dp[1][1][3] = 1;
  long long temp = 0;
  for (int i = 2; i <= n; ++i) {
    for (int k = 1; k <= (i << 1); ++k) {
      temp = 0;
      temp = temp + dp[i - 1][k][1] + dp[i - 1][k][0] + dp[i - 1][k][2] +
             dp[i - 1][k - 1][3];
      dp[i][k][0] = temp % 998244353;
      temp = 0;
      temp = temp + dp[i - 1][k][1] + dp[i - 1][k - 1][0] +
             dp[i - 1][k - 2][2] + dp[i - 1][k - 1][3];
      dp[i][k][1] = temp % 998244353;
      temp = 0;
      temp = temp + dp[i - 1][k - 2][1] + dp[i - 1][k - 1][0] +
             dp[i - 1][k][2] + dp[i - 1][k - 1][3];
      dp[i][k][2] = temp % 998244353;
      temp = 0;
      temp = temp + dp[i - 1][k][1] + dp[i - 1][k - 1][0] + dp[i - 1][k][2] +
             dp[i - 1][k][3];
      dp[i][k][3] = temp % 998244353;
      temp = 0;
    }
  }
  long long ans = 0;
  ans = ans + dp[n][lm][0] + dp[n][lm][1] + dp[n][lm][2] + dp[n][lm][3];
  ans = ans % 998244353;
  printf("%I64d\n", ans);
}
