#include <bits/stdc++.h>
using namespace std;
#define mod 998244353

int main() {
  int n, k;
  cin >> n >> k;
  vector<int> dp(n+1,0);
  dp[0]=1;
  for(int i = 1; i <= n; i++) {
    if(i >= k)dp[i]=dp[i-k];
    dp[i]+=dp[i-1];
    dp[i]%=mod;
  }
  cout << dp[n] << endl;
}