import sys
input = sys.stdin.readline

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


ANS=0

for x in range(1,K+1):
    ANS+=x*N*(K-x)*(pow(x,N-1,mod)-pow(x-1,N-1,mod))%mod
    ANS+=x*(pow(x,N,mod)-pow(x-1,N,mod)-N*pow(x-1,N-1,mod))%mod

    ANS%=mod

print(ANS)