#include <bits/stdc++.h>
using namespace std;
using ll = long long;

int main() {

    cin.tie(nullptr);
    ios::sync_with_stdio(false);

    ll N,K,mod=998244353;
    cin>>N>>K;
    K=min(K,N+1);
    vector<ll> SDP(N+1,0);
    for(int i=0;i<K;i++)SDP[i]=1;
    for(int i=K;i<=N;i++){
        SDP[i]=(SDP[i-K]+SDP[i-1])%mod;
    } 
    cout<<SDP[N]<<endl;
}