human
Give me a the Python program you requested given the following:
I found an interesting problem on https://leetcode.com/problems/friends-of-appropriate-ages/:
Some people will make friend requests. The list of their ages is given and ages[i] is the age of the ith person. 
Person A will NOT friend request person B (B != A) if any of the following conditions are true:

age[B] <= 0.5 * age[A] + 7
age[B] > age[A]
age[B] > 100 && age[A] < 100

Otherwise, A will friend request B.
Note that if A requests B, B does not necessarily request A.  Also, people will not friend request themselves.
How many total friend requests are made?
Example 1:
Input: [16,16]
Output: 2
Explanation: 2 people friend request each other.

Example 2:
Input: [16,17,18]
Output: 2
Explanation: Friend requests are made 17 -> 16, 18 -> 17.
Example 3:
Input: [20,30,100,110,120]
Output: 3
Explanation: Friend requests are made 110 -> 100, 120 -> 110, 120 -> 100.

 
Notes:

1 <= ages.length <= 20000.
1 <= ages[i] <= 120.

I tried it in Python, but could not do it. Can you solve it?
assistant
#Here is the Python program you requested.

import bisect
class Solution:
    def numFriendRequests(self, ages: List[int]) -> int:
        if not ages: 
            return 0
        cnt = 0
        N = len(ages)
        ages.sort()
        for i in range(N):
            a = ages[i]
            if a<=14: #含14歲以前不能交朋友 => 數學推導
                continue
            idx1 = bisect.bisect(ages, a)
            x = 0.5*a+7
            idx2 = bisect.bisect(ages, x)
            while idx2<N and ages[idx2]==x: #找出右boundary
                idx2 += 1
            cnt += max(0, idx1-idx2+(-1 if idx2<=i<=idx1 else 0)) #不能跟自己交朋友
        return cnt