from bisect import bisect_left
from collections import defaultdict

def calc_distance_sum(X, Y):
    Y.sort()
    prefix = [0]
    for y in Y:
        prefix.append(prefix[-1] + y)

    total = 0
    n = len(Y)
    for x in X:
        idx = bisect_left(Y, x)
        left = idx
        right = n - idx
        left_sum = x * left - prefix[idx]
        right_sum = prefix[n] - prefix[idx] - x * right
        total += left_sum + right_sum
    return total

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

    pos = defaultdict(list)
    for i, a in enumerate(A):
        pos[a].append(i)

    values = sorted(pos.keys())
    result = 0

    for i in range(len(values)):
        for j in range(i + 1, len(values)):
            v1, v2 = values[i], values[j]
            d = abs(v1 - v2)
            sum_dist = calc_distance_sum(pos[v1], pos[v2])
            result += 2 * d * sum_dist  # nhân đôi vì i < j

    print(result)

if __name__ == "__main__":
    main()