N, P = map(int, input().split())
mod = 998244353
n = 505050
fact = [1] * (n + 1)
invfact = [1] * (n + 1)
for i in range(1, n):
    fact[i + 1] = ((i+1) * fact[i]) % mod
invfact[n] = pow(fact[n], mod - 2, mod)
for i in range(n - 1, -1, -1):
    invfact[i] = invfact[i + 1] * (i + 1) % mod

def comb(n, r):
    if n < 0 or r < 0 or n - r < 0:
        return 0
    return fact[n] * invfact[r] * invfact[n - r] % mod
    
ans = 0
nokori = N
pm = 1
now = 1
cnt = 1
while now > 0:
    ans += now
    now *= comb(nokori, P) * fact[P - 1] * pow(cnt, mod - 2, mod)
    now %= mod
    ans %= mod
    nokori -= P
    cnt += 1
    
print( (fact[N] - ans) % mod )