# include <bits/stdc++.h>

const int32_t maxn = 10000005;

const int32_t mod  = 998244353;

int32_t n, k;

int64_t f[maxn], fac[maxn], ifc[maxn];

inline int64_t qpow (int64_t a, int64_t b = mod - 2) {
	
	int64_t res = 1;
	
	while (b) {
		
		if (b & 1) res = res * a % mod;
		
		a = a * a % mod, b >>= 1;
		
	}
	
	return res;
}

inline int64_t A (const int32_t x, const int32_t y) {
	return fac[x] * ifc[x - y] % mod;
}

int main () {
	
	std::cin >> n >> k; 
	
	if (k == 1) return std::cout << 1 << '\n', 0;
	
	f[0] = fac[0] = ifc[0] = 1;
	
	for (int i = 1; i <= n; ++ i) 
		f[i] = fac[i] = fac[i - 1] * i % mod;	
		
	ifc[n] = qpow (fac[n]);
	
	for (int i = n - 1; i >= 1; -- i)
		ifc[i] = ifc[i + 1] * (i + 1) % mod;
	
	for (int i = k + 1; i <= n; ++ i) 
		f[i] = (((f[i - 1] - f[i - k - 1] * A (i - 2, k - 1) % mod + mod) % mod) * i % mod + f[i - k - 1] * A (i - 2, k - 1) % mod) % mod;
	
	std::cout << f[n] << '\n';
	
	return 0;
}