Solve the programming task below in a Python markdown code block.
Chef has two integers A and B.  
Chef wants to find the minimum value of \texttt{lcm}(A, X) - \texttt{gcd}(B, X) where X is any positive integer.

Help him determine this value.

Note: \texttt{gcd}(P, Q) denotes the [greatest common divisor] of P and Q and \texttt{lcm}(P, Q) denotes the [least common multiple] of P and Q.

------ Input Format ------ 

- The first line contains a single integer T — the number of test cases. Then the test cases follow.
- The first and only line of each test case contains two space-separated integers A and B — the integers mentioned in the statement.

------ Output Format ------ 

For each test case, output the minimum value of \texttt{lcm}(A, X) - \texttt{gcd}(B, X).

------ Constraints ------ 

$1 ≤ T ≤ 10^{5}$
$1 ≤A, B ≤10^{9}$

----- Sample Input 1 ------ 
3
12 15
5 50
9 11

----- Sample Output 1 ------ 
9
0
8

----- explanation 1 ------ 
Test case $1$: For $X = 6$: $\texttt{lcm}(12, 6) - \texttt{gcd}(15, 6) = 12 - 3 = 9$ which is the minimum value required.

Test case $2$: For $X = 50$: $\texttt{lcm}(5, 50) - \texttt{gcd}(50, 50) = 50 - 50 = 0$ which is the minimum value required.

Test case $3$: For $X = 1$: $\texttt{lcm}(9, 1) - \texttt{gcd}(11, 1) = 9 - 1 = 8$ which is the minimum value required.