#pragma GCC target("avx2")
#pragma GCC optimize("Ofast,unroll-loops")
// #define _GLIBCXX_DEBUG
#include <bits/stdc++.h>
using namespace std;
#if __has_include(<atcoder/all>)
#include <atcoder/all>
using mint = atcoder::modint998244353;
istream &operator>>(istream &is, mint &a)
{
	long t;
	is >> t;
	a = t;
	return is;
}
ostream &operator<<(ostream &os, mint a)
{
	return os << a.val();
}
#endif
typedef long double ldouble;
#undef long
#define long long long
#define overload3(a, b, c, name, ...) name
#define rep1(n) for (long i = 0; i < n; i++)
#define rep2(i, n) for (long i = 0; i < n; i++)
#define rep3(i, a, b) for (long i = a; i < b; i++)
#define rep(...) overload3(__VA_ARGS__, rep3, rep2, rep1)(__VA_ARGS__)
#define per1(n) for (long i = n - 1; i >= 0; i--)
#define per2(i, n) for (long i = n - 1; i >= 0; i--)
#define per3(i, a, b) for (long i = b - 1; i >= (a); i--)
#define per(...) overload3(__VA_ARGS__, per3, per2, per1)(__VA_ARGS__)
#define ALL(a) a.begin(), a.end()
#define vec vector
template <typename T>
ostream &operator<<(ostream &os, vector<T> &a)
{
	const int n = a.size();
	rep(i, n)
	{
		os << a[i];
		if (i + 1 != n)
			os << " ";
	}
	return os;
}
template <typename T, size_t n>
ostream &operator<<(ostream &os, array<T, n> &a)
{
	rep(i, n)
	{
		os << a[i];
		if (i + 1 != n)
			os << " ";
	}
	return os;
}
template <typename T>
istream &operator>>(istream &is, vector<T> &a)
{
	for (T &i : a)
		is >> i;
	return is;
}
template <typename T, typename S>
bool chmin(T &x, S y)
{
	if (x > (T)y)
	{
		x = (T)y;
		return true;
	}
	return false;
}
template <typename T, typename S>
bool chmax(T &x, S y)
{
	if (x < (T)y)
	{
		x = (T)y;
		return true;
	}
	return false;
}
template <typename T>
void operator++(vector<T> &a)
{
	for (T &i : a)
		++i;
}
template <typename T>
void operator--(vector<T> &a)
{
	for (T &i : a)
		--i;
}
template <typename T>
void operator++(vector<T> &a, int)
{
	for (T &i : a)
		i++;
}
template <typename T>
void operator--(vector<T> &a, int)
{
	for (T &i : a)
		i--;
}
#undef endl
#define endl '\n'
void solve()
{
	int n, k;
	cin >> n >> k;
	vec<mint> d1(n + 1), d2(n + 1);
	d1[0] = 1;
	rep(i, n)
	{
		if (i + k <= n)
			d2[i + k] += d1[i];
		d2[i + 1] += d2[i];
		d1[i + 1] += d2[i + 1];
	}
	mint ans = 0;
	for (mint i : d1)
		ans += i;
	cout << ans << endl;
}
int main()
{
	// srand((unsigned)time(NULL));
	cin.tie(nullptr);
	ios::sync_with_stdio(false);
	cout << fixed << setprecision(40);
	int t = 1;
	// cin >> t;
	while (t--)
		solve();
	return 0;
}