mod = 998244353
eps = 10**-9


def main():
    import sys
    input = sys.stdin.readline

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

    pow2 = [1] * (N+1)
    for i in range(1, N+1):
        pow2[i] = (pow2[i-1] * 2)%mod

    ans = 0
    for i, a in enumerate(A):
        ans = (ans + ((a * ((pow2[i-1] * i)%mod + pow2[i])%mod)%mod * pow2[N-i-1])%mod)%mod
    print(ans)



if __name__ == '__main__':
    main()