#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
ENGG1811 Lecture 2  

Purpose: This example demonstrates chain selection 
         using if/elif/else 

Program description:
    This program asks 
    - the user to input a mark  
    - determines the grade for that mark 
    
Limitation: Does not check whether mark is valid.    
"""

# Ask the user to input a number 
mark = float(input('Please input a mark: '))

if mark >= 85:     
    grade = "HD"
elif mark >= 75:   # (mark >= 85 is false) and (mark >= 75 is true) 
    grade = "DN"
elif mark >= 65: 
    grade = "CR"
elif mark >= 50:
    grade = "PS"
else:            # Not (mark >= 50), so mark < 50
    grade = "FL"

   
print('The mark',mark,'gives the grade',grade)