N,P=map(int,input().split())

mod=998244353

FACT=[1]
for i in range(1,4*10**5+1):
    FACT.append(FACT[-1]*i%mod)

FACT_INV=[pow(FACT[-1],mod-2,mod)]
for i in range(4*10**5,0,-1):
    FACT_INV.append(FACT_INV[-1]*i%mod)

FACT_INV.reverse()

def Combi(a,b):
    if 0<=b<=a:
        return FACT[a]*FACT_INV[b]%mod*FACT_INV[a-b]%mod
    else:
        return 0

ANS=0
x=1
if P<=N:
    for i in range(0,3*10**5):
        if i*P>N:
            break
        now=i*P

        if now-P>=0:
            x=x*Combi(now,now-P)%mod

        ANS+=x*FACT_INV[i]%mod*pow(FACT[P-1],i,mod)%mod*Combi(N,i*P)%mod
        ANS%=mod
else:
    ANS=1

print((FACT[N]-ANS)%mod)