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

li = [0]*n
ans = 0
for i in range(n):
    li[i] = b[i]-a[i]

li.sort(reverse=True)
ans = li[0]
now = -li[0]

for i in range(1,n):
    #print(now,li[i],ans)
    if now == li[i]:
        continue
    elif abs(now+li[i]) % i == 0:
        ans += abs(now-li[i])
        now = li[i]
    else:
        print(-1)
        exit()

print(ans)