Write a complete and syntactically correct Python program to solve the following problem:

You want to write a Program that will take in the numeric grades of the students in your class. Since the students in

a class vary from semester to semester, there is no fixed number assigned to the number of

students. You will keep track of how many students$$ grades you input. You will stop taking input

when the student enters a grade of $-1.$

These conditions apply : No use of functions, list, a menu, break, quit, exit, sys$.$exit,

return, continue, or any other shortcuts $.$

Your program will use loops and will accomplish the following:

$1.$ Read in a numeric grade from a student.

$2.$ Convert the numeric grade to a letter grade using the grade policies in your syllabus.

$3.$ Keep a running total of the numeric grades entered.

$4.$ Keep a count of the number of grades entered.

$5.$ Issue a message that comments on the letter grade earned. As an example, you may

write $$You made an F$!$ Obviously you did not study!$$

$6.$ At the end the program will calculate a class average unless there were no grades

entered.

All input to the program will be interactive from the keyboard. The output of the program will

include the individual grades converted, the message issued to the student, a class average,

and the number of grades entered.