generous-murgi
Source: hackerearth
Difficulty: UNKNOWN_DIFFICULTY

Murgi is  very generous. Today she is very happy as she got placed in her dream company. To celebrate this moment, she decided to distribute some Candies among
beggars. She wants to distribute these Candies equally, among all the beggars. 

Initially, she had X Candies with her and after distributing them, equally among beggars, she is still left with Y Candies. Unfortunately, she forgot to count the  number of beggars. Now she wonders how many beggars were there. 

So, she goes to Mr. Prashasi for the solution of her problem. Now Mr. Prashasi gave her a list of possible number of beggars  to her.

On Behalf of Mr. Prashasi write a program to solve Murgi's problem.

Input:

First line will contain an integer T, the no. of test cases.
Next T lines will have 2 integers X and Y.

Output:

You have to output the count of possible number  of beggars. 

If there are infinite possibilities output -1.

Constraints:

1 ≤ T ≤ 50

0 ≤ X ≤ 1000000000

0 ≤ Y ≤ 1000000000

SAMPLE INPUT
1
14 2

SAMPLE OUTPUT
4

Explanation

If X=14 and Y=2 then the possible number of beggars are 3, 4, 6 and 12.