from itertools import combinations


def combination_index(N):
    N_combi = []
    N_list = list(range(N))
    for i in range(1, N+1):
        N_combi_temp = list(combinations(N_list, i))
        for j in N_combi_temp:
            N_combi.append(j)
    
    return N_combi

def sum_calc(N_combi, a):
    sum = 0
    for i in N_combi:
        line_sum = 0
        for num, j in enumerate(i):
            line_sum += a[j] * (num + 1)
        sum += line_sum
    print(sum % 998244353)



if __name__ == "__main__":
    N = int(input())
    a = list(map(int, input().split()))
    
    N_combi = combination_index(N)
    sum_calc(N_combi, a)