Write a program named combinatorics.cpp that: Prompts the user to enter integer n between 2 and 12 (inclusive) If the input is invalid, displays an error message and prompt the user to try again, as many times as necessary (use a loop to accomplish this instead of terminating the program) Prompts the user to enter integer k between 2 and n (inclusive) If the input is invalid, displays an error message and prompt the user to try again, as many times as necessary (use a loop to accomplish this instead of terminating the program) Determines and displays the following: n! P(n.) o C(nik) This program must use loops to calculate the results (do not use math functions defined in any C#libraries) Sample Output Enter an integer value for n (between 2 and 12 inclusive): 11 Invalid input, try again! Enter an integer value for n (between 2 and 12 inclusive): 5. Enter an integer value for k (between 2 and 5 inclusive): 64 Invalid input, try again! Enter an integer value for k (between 2 and 5 inclusive): 3. n! = 120 Pan, k) 60 Cin, k) 10