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

mod=998244353

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

FACT_INV=[pow(FACT[-1],mod-2,mod)]
for i in range(2*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

if K==0 or K==N:
    print(1)
    exit()

if K==1:
    if N%2==0:
        print(2)
    else:
        print(N-2)
    exit()

ANS=0

for a in range(0,N-K+1,2):
    ANS+=Combi(N-2-a,K-2)*(a+1)
    ANS%=mod
    #print(a,ANS)

print(ANS)