Number-Filter

This program will filter a list of non-negative integers such that all duplicate values are removed. Integer values will come from standard input (the keyboard) and will range in value from 0 up to 2,000,000,000. Input will be terminated by the special value, -1. Once the input is read in you should output (to the screen) the list of numbers as a sorted list (smallest to largest) with one value listed per line where all duplicates have been removed. The primary difficulty with this program is that there are an enormous number of input values and an expected large number of duplicate numbers.