write python program to check whether 3 digit number is armstrong or not

num = int(input("Enter a number: "))
if num>999:
   print('number should be include 3 digits maximum')
else:
 sum = 0  
 temp = num  
  
 while temp > 0:  
   digit = temp % 10  
   sum += digit ** 3  
   temp //= 10  
  
 if num == sum:  
    print(num,"is an Armstrong number")  
 else:  
    print(num,"is not an Armstrong number")