#include<bits/stdc++.h>
using namespace std;
using ui=unsigned int;
using ull=unsigned long long;
const int P=998244353;
const int N=1e7+3;
void add(ui &x,ui y){if((x+=y)>=P)x-=P;}
ui inv[N],f[N],g[N];
int n,K;
int main(){
    int u,v,w,x,y,z;
    ios::sync_with_stdio(0);
    cin.tie(0);cout.tie(0);
    cin>>n>>K;
    if(K==n){ui ans=1;for(ui i=1;i<=n;++i)ans=(ull)ans*i%P;printf("%u\n",ans);return 0;}
    inv[1]=1;ui ans=0;
    for(int i=2;i<=n;++i)inv[i]=(ull)inv[P%i]*(P-P/i)%P;
    f[0]=inv[n];
    for(int i=1;i<n;++i){
        ui k=f[i-1];
        if(i-K-1>=0)k=(k+P-f[i-K-1])%P;
        k=(ull)k*inv[n-i]%P;
        if(i+K>=n)add(ans,k);
        f[i]=(f[i-1]+k)%P;
    }
    for(ui i=1;i<=n;++i)ans=(ull)ans*i%P;
    printf("%u\n",ans);
    return 0;
}