# -*- coding: utf-8 -*-
"""
Created on Mon Sep 14 14:27:34 2020

@author: Sim
"""

score = int(input("Enter your score: "))

if score >= 90:
    grade = "A"
if score >= 80:
    grade = "B"
if score >= 70:
    grade = "C"
if score >= 60:
    grade = "D"
if score < 60:
    grade = "F"

print("First calculation: ", grade)

#-------------- Socond codes --------------------

if score >= 90:
    grade = "A"
#if score >= 80 and score < 90:
if 80 <= score < 90:
    grade = "B"
if score >= 70 and score < 80:
    grade = "C"
if score >= 60 and score < 70:
    grade = "D"
if score < 60:
    grade = "F"

print("Second calculation: ", grade)

#-------------- Third codes --------------------

if score >= 90:
    grade = "A"
else:
    if score >= 80:
      grade = "B"
    else:
      if score >= 70:
        grade = "C"
      else:
        if score >= 60:
          grade = "D"
        else: 
          grade = "F"
          
print("Third calculation: ", grade)

#-------------- elif codes --------------------

if score >= 90:
    grade = "A"
elif score >= 80:
    grade = "B"
elif score >= 70:
    grade = "C"
elif score >= 60:
    grade = "D"
else:
    grade = "F"

print("Fourth calculation: ", grade)