I'm trying to follow along with the lesson, and I wrote this out:

```
def digit_sum(n):
totalsum = 0
while n > 0:
digit = n % 10
totalsum = totalsum + digit
return totalsum
n = n // 10
print totalsum
```

But it gives me this error:

Oops, try again. Your function fails on digit_sum(434). It returns 4 when it should return 11.

What am I doing wrong? I've been relooking it over and over for over a day, and I can't think of what went wrong??