score = int(input("Enter your marks: \n"))

if score >= 90:
    print("Excellent! Your grade is A")
elif score >= 80:
    print("Great! Your grade is B")
elif score >= 70:
    print("Good! Your grade is C")
elif score >= 60:
    print("Your grade is D. You should work hard on you studies.")
else:
    print("You failed in the exam")