N,K=map(int,input().split())
MOD=998244353
f=[1]*N
inv=[1]*N
finv=[1]*N
for i in range(2,N):
    f[i]=f[i-1]*i%MOD
    inv[i]=MOD-(inv[MOD%i]*(MOD//i)%MOD)
    finv[i]=finv[i-1]*inv[i]%MOD

ans=0
for i in range(N):
    v=pow(i,K,MOD)*f[N-1]%MOD
    v*=finv[i]*finv[N-i-1]%MOD
    ans+=v%MOD
    ans%=MOD
print(ans)