You are given a phone number as a string `number`. `number` consists of digits, spaces `' '`, and/or dashes `'-'`.

You would like to reformat the phone number in a certain manner. Firstly, remove all spaces and dashes. Then, group the digits from left to right into blocks of length 3 until there are 4 or fewer digits. The final digits are then grouped as follows:

- 2 digits: A single block of length 2.
- 3 digits: A single block of length 3.
- 4 digits: Two blocks of length 2 each.

The blocks are then joined by dashes. Notice that the reformatting process should never produce any blocks of length 1 and produce at most two blocks of length 2.

Return the phone number after formatting.

Example 1:

    Input: number = "1-23-45 6"
    Output: "123-456"
    Explanation: The digits are "123456".
    Step 1: There are more than 4 digits, so group the next 3 digits. The 1st block is "123".
    Step 2: There are 3 digits remaining, so put them in a single block of length 3. The 2nd block is "456".
    Joining the blocks gives "123-456".

Example 2:

    Input: number = "123 4-567"
    Output: "123-45-67"
    Explanation: The digits are "1234567".
    Step 1: There are more than 4 digits, so group the next 3 digits. The 1st block is "123".
    Step 2: There are 4 digits left, so split them into two blocks of length 2. The blocks are "45" and "67".
    Joining the blocks gives "123-45-67".

Example 3:

    Input: number = "123 4-5678"
    Output: "123-456-78"
    Explanation: The digits are "12345678".
    Step 1: The 1st block is "123".
    Step 2: The 2nd block is "456".
    Step 3: There are 2 digits left, so put them in a single block of length 2. The 3rd block is "78".
    Joining the blocks gives "123-456-78".

Constraints:

- `2 <= number.length <= 100`
- `number` consists of digits and the characters `'-'` and `' '`.
- There are at least two digits in `number`.