n,k = map(int,input().split())
mod = 998244353

#nCk
def com(n,mod):
  fact = [1,1]
  factinv = [1,1]
  inv = [0,1]
  for i in range(2,n+1):
    fact.append((fact[-1]*i)%mod)
    inv.append((-inv[mod%i]*(mod//i))%mod)
    factinv.append((factinv[-1]*inv[-1])%mod)
  return fact, factinv

f,fi = com(n+10,mod)
def ncr(n,r):
  return f[n]*fi[r]%mod*fi[n-r]%mod
ans = 0
for i in range(n):
  tmp = ncr(n-1, i)
  ans += tmp * pow(i,k,mod)%mod
  ans %= mod
print(ans)