n = int(input())
num = list(map(int, input().split()))
left = 0
right = 2 * n - 1
ans = 0
for x in range(n):
    r = num[right] - num[right - 1]
    l = num[left] - num[left + 1]
    if l >= r:
        ans += l
        left += 2
    else:
        ans += r
        right -= 2
print(ans)