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?
The first line contains integer *n* (1 ≤ *n* ≤ 50000). The second line contains *n* non-negative numbers that do not exceed 10<sup class="upper-index">9</sup>, 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*.
#!/usr/bin/python3
from array import array
n = int(input())
t = [int(v) for v in input().split()]
a = array("l")
a.fromlist(t)
s = 0
k = sum(a)
m = int(k/n)
for i in range(n-1):
    d = m - a[i]
    a[i] = m
    a[i+1] -= d
    s += d
print(s)
