#include<bits/stdc++.h>
using namespace std;
int n, m;
const int mod = 998244353;
int f[10000007], sum[10000007], inv[10000007], jie[10000007];
inline int ksm(int p, int q = mod - 2) {
	int base = 1;
	while (q) {
		if (q & 1)base = base * 1ll * p % mod;
		q >>= 1;
		p = p * 1ll * p % mod;
	}
	return base;
}
signed main() {
//	freopen("b.in", "r", stdin);
//	freopen("b.out", "w", stdout);
	ios::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	cin >> n >> m;
	f[0] = 1;
	jie[0] = 1;
	for (int i = 1; i <= n; i++) jie[i] = jie[i - 1] * 1ll * i % mod;
	inv[n] = ksm(jie[n]);
	for (int i = n - 1; i >= 0; i--) {
		inv[i] = (i + 1) * 1ll * inv[i + 1] % mod;
	}
	sum[0] = jie[n - 1] * 1ll * inv[n] % mod;
	for (int i = 1; i <= n; i++) {
		f[i] = sum[i - 1];
		if (i - m - 1 >= 0) {
			f[i] = (f[i] - sum[i - m - 1] + mod) % mod;
		}
		if (i ^ n)	sum[i] = f[i] * 1ll * jie[n - i - 1] % mod * inv[n - i] % mod;
		sum[i] = (sum[i] + sum[i - 1]) % mod;
	}
	cout << f[n] * 1ll * jie[n] % mod;
}