n = int(input())
y = list(map(int, input().split()))
y.sort()
if y[0]==y[-1]:
    print(1)
    exit()
m = n // 2 + 1
y1 = y[:m]
y2 = y[m:]
ym1 = y1[len(y1) // 2]
ym2 = y2[len(y2) // 2]
ans = 0
for yk in y1:
    ans += abs(ym1 - yk)
for yk in y2:
    ans += abs(ym2 - yk)
print(ans)