A. Divisibility Problemtime limit per test1 secondmemory limit per test256 megabytesinputstandard inputoutputstandard outputYou 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.InputThe 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).OutputFor each test case print the answer — the minimum number of moves you need to do in order to make a divisible by b.ExampleInput
5
10 4
13 9
100 13
123 456
92 46
Output
2
5
4
333
0

5
10 4
13 9
100 13
123 456
92 46

2 5 4 333 0 
['math', '*800']