NOTATRI  Not a Triangle
You have N (3 ≤ N ≤ 2,000) wooden sticks, which are labeled from 1 to N. The ith stick has a length of L_{i} (1 ≤ L_{i} ≤ 1,000,000). Your friend has challenged you to a simple game: you will pick three sticks at random, and if your friend can form a triangle with them (degenerate triangles included), he wins; otherwise, you win. You are not sure if your friend is trying to trick you, so you would like to determine your chances of winning by computing the number of ways you could choose three sticks (regardless of order) such that it is impossible to form a triangle with them.
Input
The input file consists of multiple test cases. Each test case starts with the single integer N, followed by a line with the integers L_{1}, ..., L_{N}. The input is terminated with N = 0, which should not be processed.
Output
For each test case, output a single line containing the number of triples.
Example
Input: 3 4 2 10 3 1 2 3 4 5 2 9 6 0 Output: 1 0 2
For the first test case, 4 + 2 < 10, so you will win with the one available triple. For the second case, 1 + 2 is equal to 3; since degenerate triangles are allowed, the answer is 0.
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SHIVAM DIXIT:
20140428 12:59:21
O(n^2 * lgN) is accepted.... 

SHIVAM DIXIT:
20140428 12:59:21
O(n^2 * lgN) is accepted.... 

No_words:
20140111 11:43:16
Last edit: 20140111 11:51:15 

P_Quantum:
20131227 07:40:55
Easy..!! 

sobhan:
20131031 17:32:46
easy one 

Aniket Kumar:
20130604 07:05:57
n^2lgN algo for tle..


gourav:
20130101 13:19:11
are wah!! new thing learnt today... today's job done with this qstn :) 

Darky:
20130101 12:51:20
O(N^2lgN) passes. Nice question! 

Alexander Shlemov:
20120823 17:55:21
Please, note bounds of the number of subtest in one test file.

Added by:  Neal Wu 
Date:  20080803 
Time limit:  1s 
Source limit:  50000B 
Memory limit:  1536MB 
Cluster:  Cube (Intel G860) 
Languages:  All except: ERL JSRHINO 