This program takes a string and inserts in it an element separating the string in groups of a given number of characters
Default: Takes an integer and return a string representation of that integer with commas separating groups of 3 digits It uses InputInteger to make sure that the input from the user is an integer number. Example: 1234567 -> 1,234,567
Extended: Takes a string and return the string separating the characters by an element in groups