Oops, try again. Your function fails on is_prime(9). It returns True when it should return False.

that make me crazy, i tried every things

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