Quick illustration:

Nostrils:
___________
_________  |
_________| |
_________  |
Mouth:   | |
\________| |
 ________  |
/        | |
         | |
         | |
         | |
         | | 
         | |
Butthole:

That is 3 holes in total because you can “connect” any opening with 3 different one’s.