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)