import sys
input = lambda :sys.stdin.readline()[:-1]
ni = lambda :int(input())
na = lambda :list(map(int,input().split()))
yes = lambda :print("yes");Yes = lambda :print("Yes");YES = lambda : print("YES")
no = lambda :print("no");No = lambda :print("No");NO = lambda : print("NO")
#######################################################################
mod = 998244353
nn = 10**6
fact = [1] * nn
for i in range(nn - 1):
    fact[i + 1] = fact[i] * (i + 1) % mod
invfact = [1] * nn
invfact[nn - 1] = pow(fact[nn - 1], mod - 2, mod)
for i in range(nn - 1)[::-1]:
    invfact[i] = invfact[i + 1] * (i + 1) % mod
 
def binom(x, y):
    if x < 0 or y < 0 or x - y < 0:
        return 0
    return fact[x] * invfact[y] % mod * invfact[x - y] % mod

n = ni()
a = na()

f = [0] * (n+1)

for i in range(n+1):
    # for k in range(i+1):
    #     f[i] += binom(i, k) * (k+1) % mod
    #     f[i] %= mod
    if i:
        f[i] = pow(2, i-1, mod) * (i+2) % mod
    else:
        f[i] = 1
ans = 0

for i in range(n):
    ans += a[i] * f[i] * f[n-i-1] % mod
    ans %= mod

print(ans)