Python3 Straightforward Solution
Code
# Code
```python3 []
class Solution:
    def is_non_decreasing(self, nums) -> bool:
        for i in range(1, len(nums)):
            if nums[i - 1] > nums[i]:
                return False
        return True

    def minimumPairRemoval(self, nums: List[int]) -> int:
        operations_count = 0
        while not self.is_non_decreasing(nums):
            min_sum = float('inf')
            for i in range(1, len(nums)):
                min_sum = min(min_sum, nums[i - 1] + nums[i])

            for i in range(1, len(nums)):
                cur_sum = nums[i - 1] + nums[i]
                if cur_sum == min_sum:
                    nums[i - 1] = cur_sum ; del nums[i]
                    operations_count += 1
                    break
        return operations_count

```
['Python3']