n = int(input())
a = [int(i) for i in input().split()]

ans = 0

l,r = 0,2*n-1

for i in range(n):
    if a[l] - a[l+1] > a[r] - a[r-1]:
        ans += a[l]-a[l+1]
        a[l],a[l+1] = 0,10**10
        l += 2
    else:
        ans += a[r]-a[r-1]
        a[r],a[r-1] = 0,10**10
        r -= 2

print(ans)