#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
#define rep(i, n) for(ll i = 0; i < (n); i++)
#define reps(i, l, r) for(ll i = (l); i < (r); i++)
#define all(a) (a).begin(), (a).end()
#define endl "\n";
const ll INF = 2e18;
const ll mod1 = 1000000007;
const ll mod2 = 998244353;
ll dx[4] = {-1, 1, 0, 0};
ll dy[4] = {0, 0, -1, 1};
void chmin(ll& a, ll b){ if(a > b) a = b; }
void chmax(ll& a, ll b){ if(a < b) a = b; }
ll gcd(ll a, ll b) {return (b == 0 ? a : gcd(b, a % b));}
ll lcm(ll a, ll b) {return a / gcd(a, b) * b;}
void solve() {
	//ofstream cout("text.txt");
    ll N, K; cin >> N >> K;
    vector<ll>dp(N + 1, 0); dp[0] = 1;
    vector<ll>sum(N + 1, 0); sum[0] = 1;
    reps(i, 1, N + 1) {
        if (i - K >= 0) {
            dp[i] = sum[i - K];
        }
        sum[i] = (sum[i - 1] + dp[i]) % mod2;
    }
    cout << sum[N] << endl;
}
signed main() {
	cin.tie(nullptr);
	ios_base::sync_with_stdio(false);
  ll T = 1; //cin >> T;
  while(T--) solve();
}