Any ideas as to why this isn't working? I am fairly certain the median is the middle number which i am pretty sure my program returns. Below is my code and the error message I keep getting.

```
def median(lst):
lst.sort()
if len(lst) % 2 != 0:
return lst[len(lst)/2]
else:
b = lst[len(lst) / 2 + 1]
a = lst[len(lst) / 2]
c = (a + b) * .5
return c
```

Oops, try again. median([6, 8, 12, 2, 23]) returned 12 instead of 8