write a program that merges the numbers in two files and writes all the numbers into a third file. your program takes input from two different files and writes its output to a third file. each input file contains a list of numbers of type int in sorted order from the smallest to the largest. after the program is run, the output file will contain all the numbers in the two input files in one longer list in sorted order from the smallest to the largest. your program should define a function that is called with the two input-file streams and the output-file stream as three arguments. create two input files containing at least 5 numbers (in sorted order) each for testing.