p = 998244353
N = int(input())
A = list(map(int,input().split()))
A.insert(0,0)
if N==1:
    ans = A[1]%p
else:
    a = 1
    i = 0
    while i<N-2:
        a = (a*2)%p
        i += 1
    b = 0
    for i in range(1,N+1):
        b = (b+(i+1)*A[i])%p
    ans = (a*b)%p
print(ans)