Minimum Pair Removal to Sort Array I

Description

Given an array nums, you can perform the following operation any number of times:

- Select the adjacent pair with the minimum sum in nums. If multiple such pairs exist, choose the leftmost one.

- Replace the pair with their sum.

Return the minimum number of operations needed to make the array non-decreasing.

An array is said to be non-decreasing if each element is greater than or equal to its previous element (if it exists).