Given the array of integers `nums`, you will choose two different indices `i` and `j` of that array. Return the maximum value of `(nums[i]-1)*(nums[j]-1)`.

Example 1:

    Input: nums = [3,4,5,2]
    Output: 12
    Explanation: If you choose the indices i=1 and j=2 (indexed from 0), you will get the maximum value, that is, (nums[1]-1)*(nums[2]-1) = (4-1)*(5-1) = 3*4 = 12.

Example 2:

    Input: nums = [1,5,4,5]
    Output: 16
    Explanation: Choosing the indices i=1 and j=3 (indexed from 0), you will get the maximum value of (5-1)*(5-1) = 16.

Example 3:

    Input: nums = [3,7]
    Output: 12

Constraints:

- `2 <= nums.length <= 500`
- `1 <= nums[i] <= 10^3`