PROGRAMMING:The bigger the better
*Your task is quite simple. As long as no more than n ($$n / Leq 100 $$) matches are used to set up a positive integer as large as possible and divisible by M ($$m / Leq 3000 $$). Note that matches can only be placed in the following shape.
![ QQ picture 20191115191636. PNG] (~ / 9a84df8d-5a61-4dbe-a741-49158c0c19d7. PNG)
###Input format:
The input contains T group samples.
Each group of samples contains two positive integers n and m.
###Output format:
Output a total of T lines, each line output in accordance with the requirements of the maximum number of pendulum; If there is no solution, output - 1.
###Input example:
Here is a set of inputs. For example:
```in
two
6 3
5 6
```
###Output example:
The corresponding output is given here. For example:
```out
one hundred and eleven
-1
```
answer：If there is no answer, please comment
![ QQ picture 20191115191636. PNG] (~ / 9a84df8d-5a61-4dbe-a741-49158c0c19d7. PNG)
###Input format:
The input contains T group samples.
Each group of samples contains two positive integers n and m.
###Output format:
Output a total of T lines, each line output in accordance with the requirements of the maximum number of pendulum; If there is no solution, output - 1.
###Input example:
Here is a set of inputs. For example:
```in
two
6 3
5 6
```
###Output example:
The corresponding output is given here. For example:
```out
one hundred and eleven
-1
```
answer：If there is no answer, please comment