# >= 90 A
# >= 80 B (but <90)
# >= 70 C
# >= 60 D
# otherwise F

score = input('What score did you get out of 100')
score = float(score) # coverts the string to an float

if score >= 90:
    print('Your letter grade is A')
elif score >= 80:
    print('Your letter grade is B')
elif score >= 70:
    print('Your letter grade is C')
elif score >= 60:
    print('Your letter grade is D')
else:
    print('Your letter grade is F')