def naive(A):
    N = len(A)
    ret = [0] * N
    for i in range(1<<N):
        use = []
        for j in range(N):
            if(i>>j & 1 == 0):continue
            ret[j] += len(use) + 1
            use.append(j)
    return ret

MOD = 998244353
N = int(input())
A = list(map(int,input().split()))

ans = 0
for i in range(N):
    ans += A[i] * (pow(2, N-1, MOD) + pow(2, N-2, MOD) * i)
    ans %= MOD
print(ans)