from threading import main_thread
class Solution:
    def search(self , nums: List[int], target: int) -> int:
        st=0
        en=len(nums)
        if len(nums)==0:
            return -1
        while st<en:
            mid=(en+st)//2
            if nums[mid]>=target:
                en=mid
            else:
                st=mid+1
        if nums[st]==target:
            return st
        else:
            return -1