7.4 code practice question 1 edhesive Instructions
Write a program that prompts the user to input a letter grade in either capital or lowercase. Your program should then output the correct number of the GPA. See the table below for possible inputs and expected outputs. Your program should define at least one function named GPAcalc that is called from your main program.

The GPAcalc function should take exactly one parameter—a string for the letter grade as lower or upper case. It will return either an integer for the GPA value or a string Invalid, if the letter grade parameter is invalid.

Input: Letter Grade Expected output: GPA value
A or a 4
B or b 3
C or c 2
D or d 1
F or f 0
Anything else Invalid
Sample Run 1
Enter your Letter Grade: a
Your GPA score is: 4
Sample Run 2
Enter your Letter Grade: A
Your GPA score is: 4
Sample Run 3
Enter your Letter Grade: C
Your GPA score is: 2
Sample Run 4
Enter your Letter Grade: G
Your GPA score is: Invalid