题目描述

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?

翻译：

给定两个正整数$a,b$，找到非负整数$k$使$a+k$与$b+k$的最小公倍数最小，如有多解输出最小的$k$

输入格式

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

输出格式

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.

####样例

输入样例1

6 10

输出样例1

2

输入样例2

21 31

输出样例2

9

输入样例3

5 10

输出样例3

0

说明与提示

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.