CF1152C.Neko does Maths

Neko loves divisors. During the latest number theory lesson, he got an interesting exercise from his math teacher.

Neko has two integers $a$ and $b$. His goal is to find a non-negative integer $k$ such that the least common multiple of $a+k$ and $b+k$ is the smallest possible. If there are multiple optimal integers $k$, he needs to choose the smallest one.

Given his mathematical talent, Neko had no trouble getting Wrong Answer on this problem. Can you help him solve it?

Neko 非常喜欢约数。在最近的一节数论课上，他的数学老师给他布置了一道有趣的习题。

Neko 有两个整数 $a$ 和 $b$。他的目标是找到一个非负整数 $k$，使得 $a+k$ 与 $b+k$ 的最小公倍数（LCM）尽可能小。如果存在多个使最小公倍数达到最小值的最优整数 $k$，他需要选择其中最小的一个。

凭借其数学天赋，Neko 在这道题上毫无困难地得到了“答案错误”（Wrong Answer）。你能帮他解决这个问题吗？

The only line contains two integers $a$ and $b$ ($1 \le a, b \le 10^9$).

唯一的一行包含两个整数 $a$ 和 $b$（$1 \le a, b \le 10^9$）。

Print the smallest non-negative integer $k$ ($k \ge 0$) such that the lowest common multiple of $a+k$ and $b+k$ is the smallest possible.

If there are many possible integers $k$ giving the same value of the least common multiple, print the smallest one.

输出使得 $a+k$ 与 $b+k$ 的最小公倍数（LCM）取到最小值的最小非负整数 $k$（即 $k \ge 0$）。

若存在多个 $k$ 值使得最小公倍数相同，则输出其中最小的一个。

In the first test, one should choose $k = 2$, as the least common multiple of $6 + 2$ and $10 + 2$ is $24$, which is the smallest least common multiple possible.

在第一个测试用例中，应选择 $k = 2$，因为 $6 + 2$ 与 $10 + 2$ 的最小公倍数为 $24$，这是可能的最小公倍数。