mod = 998244353
def f(l):
  res = pow(2,l,mod) + l * pow(2,l-1,mod)
  res %= mod
  return res
N = int(input())
A = list(map(int,input().split()))

ans = 0
for l in range(N):
  r = N - 1 - l
  res = f(l) * f(r)
  res %= mod
  res *= A[l]
  res %= mod
  ans += res
  ans %= mod
print(ans)