Divisibility Problem
Description
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.
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 $b$ ($1 \le a, b \le 10^9$).
For each test case print the answer — the minimum number of moves you need to do in order to make $a$ divisible by $b$.
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 $b$.
Samples
5
10 4
13 9
100 13
123 456
92 46
2
5
4
333
0