Given an integer array `nums`, return the number of elements that have both a strictly smaller and a strictly greater element appear in `nums`.

Example 1:

    Input: nums = [11,7,2,15]
    Output: 2
    Explanation: The element 7 has the element 2 strictly smaller than it and the element 11 strictly greater than it.
    Element 11 has element 7 strictly smaller than it and element 15 strictly greater than it.
    In total there are 2 elements having both a strictly smaller and a strictly greater element appear in nums.

Example 2:

    Input: nums = [-3,3,3,90]
    Output: 2
    Explanation: The element 3 has the element -3 strictly smaller than it and the element 90 strictly greater than it.
    Since there are two elements with the value 3, in total there are 2 elements having both a strictly smaller and a strictly greater element appear in nums.

Constraints:

- `1 <= nums.length <= 100`
- `-105 <= nums[i] <= 105`