LCM Problem

Description:

Input:

The first line contains one integer $$$t$$$ ($$$1 \le t \le 10000$$$) — the number of test cases.

Each test case is represented by one line containing two integers $$$l$$$ and $$$r$$$ ($$$1 \le l < r \le 10^9$$$).

Output:

For each test case, print two integers:

• if it is impossible to find integers $$$x$$$ and $$$y$$$ meeting the constraints in the statement, print two integers equal to $$$-1$$$;
• otherwise, print the values of $$$x$$$ and $$$y$$$ (if there are multiple valid answers, you may print any of them).

Sample Input:

4
1 1337
13 69
2 4
88 89

Sample Output:

6 7
14 21
2 4
-1 -1