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

I get the error that says it returns 4 instead of 11. Also I tried using "while" instead of "if" in line 6, but it goes to infinite loop. What is my mistake? Where should I correct it.

```
def digit_sum(n):
n = int(n)
sums = 0
rem = n % 10
quo = n // 10
if (quo > 9):
n = rem
sums = sums + rem
return sums
```