Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.
If you've seen these problems, a virtual contest is not for you - solve these problems in the archive.
If you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.
Never use someone else's code, read the tutorials or communicate with other person during a virtual contest.
You are given two positive integers $$$a$$$ and $$$b$$$. In one move you can increase $$$a$$$ by $$$1$$$ (replace $$$a$$$ with $$$a+1$$$). Your task is to find the minimum number of moves you need to do in order to make $$$a$$$ divisible by $$$b$$$. It is possible, that you have to make $$$0$$$ moves, as $$$a$$$ is already divisible by $$$b$$$. You have to answer $$$t$$$ independent test cases.
Input
The first line of the input contains one integer $$$t$$$ ($$$1 \le t \le 10^4$$$) — the number of test cases. Then $$$t$$$ test cases follow.
The only line of the test case contains two integers $$$a$$$ and $$$b$$$ ($$$1 \le a, b \le 10^9$$$).
Output
For each test case print the answer — the minimum number of moves you need to do in order to make $$$a$$$ divisible by $$$b$$$.