#include<bits/stdc++.h>

#define ll long long
using namespace std;

const ll Mod = 998244353;
const int MAXN = 1e7+10; 

int n,k;

ll fac[MAXN],inv[MAXN];
ll dp[MAXN],S;

ll qpow(ll a,ll b){ ll res = 1; while(b){ if(b&1)res=res*a%Mod; a=a*a%Mod,b>>=1; } return res % Mod; }

int main(){
	//freopen("b.in","r",stdin);
	//freopen("b.in","w",stdout);
	scanf("%d%d",&n,&k);
	fac[0] = inv[0] = 1;
	for(int i = 1;i <= n;i++) fac[i] = fac[i-1]*i % Mod;
	inv[n] = qpow(fac[n],Mod-2); for(int i = n-1;i;i--) inv[i] = inv[i+1]*(i+1)%Mod;
	
	dp[0] = 1; S = (dp[0]*fac[n-1]) % Mod;
	for(int i = 1;i <= n;i++){
		dp[i] = S*inv[n-i] % Mod;
		if(i < n){
			if(i >= k) S = (S + (Mod-1ll*dp[i-k]*fac[n-i+k-1]%Mod)%Mod ) % Mod;
			S = (S + dp[i]*fac[n-i-1]%Mod)%Mod;
		}
	}printf("%lld\n",dp[n]%Mod);
	return 0;
}