try:
    score = float(input("Enter Score: "))
except:
    print("score out of range")
    quit()
if score==0.9:
    print("A")
elif score==0.8:
    print("B")
elif score==0.7:
    print("C")
elif score==0.6:
    print("D")
elif score<0.6:
    print("F")
else:
    print("Score value out of bounds")
    quit()




