Write an auto$-$grader in Python.

It accepts input score from keyboard with a prompt as you like.

Convert the input into Integer and assign it to an variable.

Check the input score if is valid $($less or equal than $100,$ and greater or equal than $0)$

Use if$-$elif$-$else structure to grade this student score and print out the result with some encouraging words as you like.

Criteria: greater than $89$ : A$,$ greater than $79$: B$,$ greater than $69$: C$,$ greater than $59$: D$,$ otherwise : F$.$