if 循环
age_of_princal = 56
guess_age = int(input(">>:"))
if guess_age == age_of_princal:
print("Yes,you got it.")
else:
print("No,it's wrong.")
age_of_princal = 56
guess_age = int(input(">>:"))
if guess_age == age_of_princal:
print("Yes,you got it.")
elif guess_age > age_of_princal:
print("You shoud try samller.")
else:
print("You try bigger.")
score = int(input("score:"))
if score > 90:
print("A")
elif score > 80:
print("B")
elif score > 60:
print("C")
else:
print("D")