【cf440B】Balancer

2014年6月4日9100

Petya has k matches, placed in n matchboxes lying in a line from left to right. We know that k is divisible by n. Petya wants all boxes to have the same number of matches inside. For that, he can move a match from its box to the adjacent one in one move. How many such moves does he need to achieve the desired configuration?

Input

The first line contains integer n (1 ≤ n ≤ 50000). The second line contains n non-negative numbers that do not exceed 109, the i-th written number is the number of matches in the i-th matchbox. It is guaranteed that the total number of matches is divisible by n.

Output

Print the total minimum number of moves.

Sample test(s)
input

output

题解

不解释