#include<bits/stdc++.h>
using namespace std;
namespace my_std{
#define mems(x,y) memset(x,y,sizeof x)
#define Mp make_pair
#define eb emplace_back
#define gc getchar
#define pc putchar
#define fi first
#define se second
#define il inline
#define rep(i,a,b) for(int i=(a);i<=(b);i++)
#define drep(i,a,b) for(int i=(a);i>=(b);i--)
#define go(i,u) for(int i=head[u];i;i=e[i].nxt)
	typedef long long ll;
	typedef pair<int,int> pii;
	template<typename T>
	il void read(T &x){
		int f=1;x=0;char c=gc();
		while(c<'0'||c>'9'){
			if(c=='-'){
				f=-1;
			}
			c=gc();
		}
		while(c>='0'&&c<='9'){
			x=x*10+c-48,c=gc();
		}
		x*=f;
	}
	template<typename T,typename ...Args>
	void read(T &x,Args &...args){
		read(x),read(args...);
	}
	template<typename T>
	il void write(T x){
		char buf[43];int len=0;
		if(x<0){
			pc('-'),x=-x;
		}
		do{
			buf[++len]=x%10,x/=10;
		}while(x);
		while(len){
			pc(buf[len--]+'0');
		}
	}
}
using namespace my_std;
const int N=1e7+7,M=-1,inf=0x3f3f3f3f,mod=998244353;
int n,m,dp[N];
int fac[N],ifac[N];
il int Mod(int x,int y){return x+y>=mod?x+y-mod:x+y;}
il int binom(int x,int y){if(x<0||y<0||x<y){return 0;}return 1ll*fac[x]*ifac[y]%mod*ifac[x-y]%mod;}
il int qpow(int x,int y){int ret=1;while(y){if(y&1){ret=1ll*ret*x%mod;}x=1ll*x*x%mod,y>>=1;}return ret;}
void initFac(int n){fac[0]=1;rep(i,1,n){fac[i]=1ll*fac[i-1]*i%mod;}ifac[n]=qpow(fac[n],mod-2);drep(i,n-1,0){ifac[i]=1ll*ifac[i+1]*(i+1)%mod;}}
void Yorushika(){
	read(n,m);
	initFac(n);
	dp[0]=1;
	int s=fac[n-1];
	rep(i,1,n){
		dp[i]=1ll*s*ifac[n-i]%mod;
		if(i<n){
			s=Mod(s,1ll*dp[i]*fac[n-i-1]%mod);
			if(i>=m){
				s=Mod(s,mod-1ll*dp[i-m]*fac[n-i+m-1]%mod);
			}
		}
	}
	printf("%d\n",dp[n]);
}
signed main(){
	int t=1;
	//read(t);
	while(t--){
		Yorushika();
	}
}