def main2(n,k,a):
  mod=998244353
  num=sum(a)%mod
  ans=num
  # num+num*2+num*2^2+num*2^3+...+num*2^(k-1)
  ans+=num*(pow(2,k,mod)-1)
  return ans%mod
  for i in range(k):
    ans+=num*pow(2,i)
    ans%=mod
  return ans
if __name__=='__main__':
  n,k=map(int,input().split())
  a=list(map(int,input().split()))
  ret2=main2(n,k,a)
  print(ret2)