N = int(input())
A = list(map(int, input().split()))
mod = 998244353
two = [1] * (N + 1)
for i in range(N):
    two[i + 1] = (two[i] * 2) % mod

def f(x):
    return (two[x] + x * two[x-1]) % mod

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

print(ans)