#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
  #include "settings/debug.cpp"
  #define _GLIBCXX_DEBUG
#else
  #define Debug(...) void(0)
#endif
#define rep(i, n) for (int i = 0; i < (n); ++i)
using ll = long long;
using ull = unsigned long long;

#include <atcoder/modint>
using mint = atcoder::modint998244353;

int main() {
  int n, k;
  cin >> n >> k;
  vector<mint> dp(n + 1, 0);
  dp[0] = 1;
  rep(i, n + 1) {
    if (i > 0) dp[i] += dp[i - 1];
    if (i >= k) dp[i] += dp[i - k];
  }
  cout << dp[n].val() << endl;
  return 0;
}