C++ Matrix Multiplication and I/O

I need a program with source code commented on every step so that I can understand the process. The project is read a 4X4 matrix from [login to view URL] and another 4X4 matrix from m2.txt. Call a function to add these matrices and write the results to a new file called [login to view URL] then call a function to multiplies these matrices and write the results to a new file called [login to view URL] Then exit the program. I am using DevC++ as my compiler so please make the code compatible with my compiler!!