Ok so for the intro both of these two riffs sound right but are slightly different...does anyone by any chance know which is the right one?? or cloest to it.

Riff 1:


C----------------------------------------
G-----------------------------------------
C---------------------------------------
F ---10---9-----------7----12--10--9-10---
A ---------------10------------------------
D 77----7----77----7----7----7---7-------



Riff 2:

C------------------------------------
G----------------------------------
C----------------------------------
F ---10--9---5--7--12-10-9-10----
A 00---0--00--0--0---0--0---------
D------------------------------------


anyone?? all help is appreciated.