n = int(input("Enter your number: "))
## try to test n = 12, 371, 153.
# since we modify n in the loop, we cannot extract the input number again
# we need a variable origin_n to store the original input number
# for comparison later
origin_n = n
sum = 0
while n != 0:
## extract the last digit of the input number
## adjusting n to avoid infinite loop
## also adjusting n so that in the next loop, we can extract the next last digit
remainder = n % 10 ## for example n = 123 --> then remainder = 3
n = n // 10 ## for example: n = 123 --> then n = 12
## update sum
sum += remainder ** 3
if sum == origin_n:
print(origin_n, "is an Amstrong number")
else:
print("not an Amstrong number")