#include <bits/stdc++.h>
#define rep(i,n) for(int i=0;i<(n);++i)
using namespace std;
using ll = long long;

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

int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    
    int n,k;
    cin >> n >> k;
    vector<mint> dp(n+2,0);
    dp[0] = 1;
    vector<mint> sum(n+2,0);
    rep(i,n+1){
        dp[i] += sum[i];
        sum[min(i+k,n+1)]+=dp[i];
        sum[i+1] += sum[i];

    }
    mint ans = 0;
    rep(i,n+1) ans += dp[i];
    cout << ans.val() << endl;
    
}