#include<bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
const ll mod = 998244353;
int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    fixed(cout).precision(12);
    ll N, K; cin >> N >> K;
    vector<ll> dp(N + 1, 0);
    dp[0] = 1;
    for(int i = 1; i <= N; i++) {
        dp[i] = dp[i - 1];
        if(i - K >= 0) dp[i] += dp[i - K];
        dp[i] %= mod;
    }
    cout << dp[N] << endl;
}