//qoj8023
#include <bits/stdc++.h>
using namespace std;

const int N = 1e7 + 10;
typedef long long ll;
const ll P = 998244353;
int n, k;
ll fac, inv[N], f[N];

ll qp(ll x, ll y){
    ll ans = 1;
    while(y){
        if(y & 1){
            ans = ans * x % P;
        }
        x = x * x % P;
        y >>= 1;
    }
    return ans;
}

int main(){
    scanf("%d%d", &n, &k);
    fac = 1;
    for(int i = 1; i <= n; ++ i){
        fac = fac * i % P;
    }
    inv[1] = 1;
    for(int i = 2; i <= n; ++ i){
        inv[i] = (P - P / i) * inv[P%i] % P;
    }
    f[1] = inv[n];
    for(int i = 2; i <= n; ++ i){
        ll pr = (i - k - 1 >= 0) ? f[i-k-1] : 0;
        f[i] = (f[i-1] - pr + P) * inv[n-i+1] % P;
        f[i] = (f[i] + f[i-1]) % P;
    }
    printf("%lld\n", (f[n] - f[n-k] + P) * fac % P);
    return 0;
}