class Solution:
    def hIndex(self, citations):
        """
        :type citations: List[int]
        :rtype: int
        """
        n = len(citations)
        l,r=0,n-1
        h = 0 
        while l<=r:
            mid=l+(r-l)//2
            h = max(h,min(citations[mid],n-mid))
            if
 
 citations[mid]<n-mid:
                l=mid+1 
            else:
                r=mid-1 
        return h