score = input(" enter a Score:")
x = float(score)
if x >= 0.9:
    print("A")
elif x >= 0.8:
    print("B")
elif x >= 0.7:
    print("C")
elif x >= 0.6:
    print("D")
elif x < 0.6:
    print("F")
else:
    print("out of the range")
