Write a code in python that solves one the following problems: Take values of length and width of a rectangle need to be taken from the user and the user needs to be told if their rectangle is a square or not.

A school has following rules for grading system:
a. Below 25 - F
b. 25 to 45 - E
c. 45 to 50 - D
d. 50 to 60 - C
e. 60 to 80 - B
f. Above 80 - A
Ask user to enter a score and print the corresponding grade.

Write a program that prints the absolute value of a number entered by a user
(example: input: 1 output: 1 input: -1 output: 1 )