Use Euler's phi function to save yourself the trouble of counting.
...or count to save yourself the trouble of using Euler's phi function... just kidding :-P
im still confused on this one, can you explain a little more about how you found your answer
i got 32 can any one verify?
If GF(81)* has 80 elements, $ \phi(80)=32 $.
I got 32 too.