题号：NC223981
时间限制：C/C++/Rust/Pascal 1秒，其他语言2秒
空间限制：C/C++/Rust/Pascal 256 M，其他语言512 M
64bit IO Format: %lld
题目描述
Call a set of positive integers triangular if it has size at least three and, for all triples of distinct integers from the set, a triangle with those three integers as side lengths can be constructed.
Given a set of positive integers, compute the number of its triangular subsets
输入描述:
The first line of input contains a single integer n (1 ≤ n ≤ 50), which is the number of integers inthe set.
Each of the the next n lines contains a single integer x (1 ≤ x ≤ 109 ). These are the elements ofthe set. They are guaranteed to be distinct.
输出描述:
Output a single integer, which is the number of triangular subsets of the given set.
示例2
输入
复制
10
27
26
17
10
2
14
1
12
23
39