n = int(input())
Y = list(map(int, input().split()))
Y.sort()

import math

if n%2 == 1:
    ans = 0
    for i in range(n):
        ans += abs(Y[i]-Y[n//2])
else:
    y1 = math.floor((Y[n//2-1]+Y[n//2])/2)
    y2 = math.ceil((Y[n//2-1]+Y[n//2])/2)
    ans1 = 0
    ans2 = 0
    for i in range(n):
        ans1 += abs(Y[i]-y1)
        ans2 += abs(Y[i]-y2)
    ans = min(ans1, ans2)
print(ans)