def main():
    N = int(input())
    A = list(map(int, input().split()))
    partial_results = [-1] * 8
    sum_ = 0
    for base in A:
        if partial_results[base-1] == -1:
            partial = sum(base ** a_elm for a_elm in A)
            partial_results[base-1] = partial
        sum_ += partial_results[base-1]
    print(sum_)


if __name__ == "__main__":
    main()