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


fact=[1 for _ in range(M+1)]
factinv=[1 for _ in range(M+1)]

a=1
b=1
p=998244353
for i in range(M):
  a*=(i+1)
  a%=p
  b*=pow(i+1,p-2,p)
  b%=p
  fact[i+1],factinv[i+1]=a,b
  
def comb(n,k,p):
  return fact[n]*(factinv[k]*factinv[n-k])%p
  
ans=0
for i in range(M):
	ans+=pow(i,K,p)*comb(M-1,i,p)%p
	ans%=p
print(ans)