implement in C++

Exercise 3: 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 smallest to largest in the format given below. Your program should definc a function that is called with the two input-file streams and the output-file stream as three arguments. Please use the following two input files given in the Assignment Lab 3: Lablnput3-3.txt and Lablnput3-4.txt. Recommended (optional, no submission needed): *All self-test exercises of Ch. 6 Practice Programs: 62,67 Programming Projects: 6.2,6.4, 6.8