def main():
    n = int(input())
    if n > 100:
        exit()
    a = list(map(int, input().split()))
    total = 0
    for i in range(1, n + 1):
        for j in range(1, n + 1):
            total += abs(i - j) * abs(a[i - 1] - a[j - 1])
    print(total)


if __name__ == '__main__':
    main()