import statistics
N = int(input())
Y = [int(y) for y in input().split()]

Y.sort()
cnt = 0
prev = Y[0]-1
for y in Y:
    if y == prev:
        continue
    cnt += 1
    prev = y

def f(L, a, b):
    res = 0
    a = int(a)
    b = int(b)
    for l in L:
        res += min(abs(l-a), abs(l-b))
    return res

if cnt == 1:
    ans = 1
elif cnt == 2:
    ans = 0
else:
    if N%2 == 0:
        ans = f(Y, statistics.median(Y[:N//2]), statistics.median(Y[N//2:]))
    else:
        ans = min(f(Y, statistics.median(Y[:N//2]), statistics.median(Y[N//2:])), f(Y, statistics.median(Y[:N//2+1]), statistics.median(Y[N//2+1:])))
print(ans)