Maximum of three integers

Your task is to design a program that will find maximum of three positive integers.

You should do input validation. Make sure that users enter a positive numbers.

You will have a main module and a function named max that accepts three integer values as arguments. The max function should return the value that is greater of the three. For example, if 7,12 and 9 are passed as arguments to the function, the function should return 12.
You should submit pseudocode and flowchart. In a MS Word file, please copy and paste the following statement and put your initials to the bottom of the statement.