7-4. 50948 - Translate Score into Grade

Translate Score into Grade

Write a program, which asks for a student score. Score is a number from 0-100. Translate the score into grade according to the next limits:
score >= 90 is "A"
score >= 80 is "B"
score >= 70 is "C"
score >= 60 is "D"
anything else is "F"

if the score is 100 print "Perfect score!”

Input: A positive integer number.

Output: The letter grade or the message "Perfect score!” for 100 points;

Sample Input1:	Sample Input2:	Sample Input3:
85	30	100
Sample  Output1:	Sample  Output2:	Sample  Output3:
B	F	Perfect score!