#include <iostream>
#include <vector>

using namespace std;
constexpr int MOD = 998244353;

int main() {
  int n, k;
  cin >> n >> k;

  vector<int> dp(n + 1, 0);
  for (int i = 0; i < min(n + 1, k); ++i) dp[i] = 1;

  for (int i = k; i <= n; ++i) {
    dp[i] = ((dp[i] + dp[i - k]) % MOD + dp[i - 1]) % MOD;
  }

  cout << dp[n] << endl;
  return 0;
}