#include <bits/stdc++.h>
using namespace std;
const int modd = 998244353;
const int maxn = 2000 + 10;
int n, k;
long long dp[maxn][maxn][4];
void solve() {
  dp[1][1][0] = dp[1][1][3] = 1;
  dp[1][2][1] = dp[1][2][2] = 1;
  for (int i = 2; i <= n; i++) {
    dp[i][1][0] = dp[i][1][3] = 1;
    dp[i][1][1] = dp[i][1][2] = 0;
    for (int j = 2; j <= k; j++) {
      dp[i][j][0] = (dp[i - 1][j][0] % modd + dp[i - 1][j][1] % modd +
                     dp[i - 1][j][2] % modd + dp[i - 1][j - 1][3] % modd) %
                    modd;
      dp[i][j][1] = (dp[i - 1][j - 1][0] % modd + dp[i - 1][j][1] % modd +
                     dp[i - 1][j - 2][2] % modd + dp[i - 1][j - 1][3] % modd) %
                    modd;
      dp[i][j][2] = (dp[i - 1][j - 1][0] % modd + dp[i - 1][j - 2][1] % modd +
                     dp[i - 1][j][2] % modd + dp[i - 1][j - 1][3] % modd) %
                    modd;
      dp[i][j][3] = (dp[i - 1][j - 1][0] % modd + dp[i - 1][j][1] % modd +
                     dp[i - 1][j][2] % modd + dp[i - 1][j][3] % modd) %
                    modd;
    }
  }
}
int main() {
  cin >> n >> k;
  solve();
  cout << (dp[n][k][0] % modd + dp[n][k][1] % modd + dp[n][k][2] % modd +
           dp[n][k][3] % modd) %
              modd
       << endl;
}
