Given a list of integers, return the largest product that can be made by multiplying any three integers.

Write a function `solve`

that have the following parameter(s):

1.) *arr = an array of integer*

**Example**

Input:

`[-10, -10, 5, 2]`

Output:

`500`

**Explanation**

An array is given [-10, -10, 5, 2]. It will return `500`

, since that's,
-10 * -10 * 5.

**Example**

Input:

`[8, -1, 37, 9, 100,]`

Output:

`33300`

**Explanation**

An array is given [8, -1, 37, 9, 100,]. It will return `33300`

, since that's,

37 * 9 * 100.

**Constraints**

• The length of an array should be greater than 0 and less than 100.

• The elements of an array should be greater than -1000 and less than 1000.