N = int(input())
Y = list(map(int, input().split()))
Y.sort()
if N % 2 == 1:
    H = Y[(N + 1) // 2 - 1]
    print(sum([abs(Y[i] - H) for i in range(N)]))
else:
    H1 = Y[N // 2 - 1]
    H2 = Y[N // 2]
    print(min(sum([abs(Y[i] - H1) for i in range(N)]), sum([abs(Y[i] - H2) for i in range(N)])))