21147번 - Triangular Collection 다국어

문제

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.

입력

The first line of input contains a single integer $n$ (1ドル \le n \le 50$), which is the number of integers in the set.

Each of the the next $n$ lines contains a single integer $x$ (1ドル \le x \le 10^9$). These are the elements of the set. They are guaranteed to be distinct.

출력

Output a single integer, which is the number of triangular subsets of the given set.

제한

힌트