Using the Alternate Binary Search Approach (Optional)

class Solution:
    def search(self, nums: List[int], target: int) -> int:
        
        l, r =0,len(nums)-1
        
        while l < r:
            
            m = l + (r-l)//2
            
        
            # true value
            if nums[m] >= target:
                r = m 
            
            else:
                l = m + 1
                
               
       
        # Return the index.
        return r if nums[r] == target else -1