#!/usr/bin/env python
# coding=utf-8

"""311. Biclinic Integral Quadrilaterals
https://projecteuler.net/problem=311

ABCD is a convex, integer sided quadrilateral with 1 ≤ AB < BC < CD < AD.  
BD has integer length. O is the midpoint of BD. AO has integer length.  
We'll call ABCD a _biclinic integral quadrilateral_ if AO = CO ≤ BO = DO.  

For example, the following quadrilateral is a biclinic integral quadrilateral:  
AB = 19, BC = 29, CD = 37, AD = 43, BD = 48 and AO = CO = 23.

Let B(N) be the number of distinct biclinic integral quadrilaterals ABCD that
satisfy AB2+BC2+CD2+AD2 ≤ N.  
We can verify that B(10 000) = 49 and B(1 000 000) = 38239.

Find B(10 000 000 000).
"""
