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.
The first line of input contains a single integer n (1≤n≤50), which is the number of integers in the set.
Each of the the next n lines contains a single integer x (1≤x≤109). These are the elements of the set. They are guaranteed to be distinct.
Output a single integer, which is the number of triangular subsets of the given set.