做这题是第一次发现round（）的局限性

import math

while True:
    try:
        num1 = float(input())

        num2 = (math.floor(num1*10) % 10)
        if(num2 >= 5):
            print(math.ceil(num1))
        else:
            print(math.floor(num1))
    except:
        break