mod=998244353
n,k=map(int,input().split())
f=[0]*(k+2)
for x in range(1,k+1):
    f[x]=pow((x-1+k-x+1),n,mod)-pow(x-1,n,mod)-n*(k-x+1)*pow(x-1,n-1,mod)
    f[x]%=mod

ans=0
for x in range(1,k+1):
    ans+=x*(f[x]-f[x+1])
    ans%=mod
print(ans)