C++ :: Reading From 2 Files And Merging

The directions are to write a program that reads sorted integers from two separate files and merge the contents of the file to an output file (third file). The only standard output will be any errors to be reported and a “FINISHED” statement after all items have been processed.

file1.txt
2
4
6
8
10

file2.txt
1
5
11
12
15

Output.txt
1
2
4
5
6
8
10
11
12
15

This is the code I have so far, but it is not working, and I have put the two txt files in the same directory as my .cpp file. It is not working though still. What have I done wrong and how can I fix it to read these integers from the two numbers and merge the contents into a third file?

#include <iostream>
#include <fstream>
using namespace std;
int main() {
int num1;
int num2;
ifstream inputFile;

[Code] ....