Write a program that reads a list of integers and outputs the number of triples in the list.
A triple is three consecutive integers in ascending order — 3,4,5 is a triple, but 5,4,3 and 2,4,6 are not.
The first line contains the size of the list.
The rest of the lines contain the elements of the list.
Output a single integer value that represents the number of triples in the list.
In the example below, there are two triples: 4,5,6 and 5,6,7.