<Below this line, add a link to the EXACT exercise that you are stuck

is_prime

Oops, try again. Your function fails on is_prime(0). It returns None when it should return False.

```
def is_prime(x):
if x == 2 or x == 3:
return True
elif x > 2:
for n in range(2, x-1):
if x%n == 0:
return False
break
return True
is_prime(9)
```