def minimal_walk_distance(n, coins):
    leftmost = min(coins)
    rightmost = max(coins)


    route1 = (rightmost - leftmost) + min(abs(leftmost), abs(rightmost))

    return 2 * (rightmost - leftmost) + min(abs(leftmost), abs(rightmost))

n = int(input())
coins = list(map(int, input().split()))

print(minimal_walk_distance(n, coins))