My error message is: Oops, try again. Your function fails on is_prime(3). It returns None when it should return True.

I don't understand why it doesn't work. Please help me.

```
def is_prime(x):
if x < 2:
return False
elif x == 2:
return True
for n in range(2, (x - 1)):
if x % n == 0:
return False
elif x == n:
return False
else:
return True
```