Number guessing game in python

from random import *
a = randint(1,100)
guess = 0
while True:
    num = input("guessed number:")
    guess += 1
    if not num.isdigit():
        print("please input a number")
    elif int( num) < 0 or int(num) >=100:
        print("The entered number is out of range!")
    else:
        if int(num) == a:
            print("Congratulations on your guess!")
        elif int( num) > a:
            print("The number you entered is too large!")
        elif int(num) < a:
            print("The number you entered is too small!")
        else:
            print("An unknown error has occurred in the system, please contact the staff personnel to deal with it!")