A little sauce and salt to taste!
I hope i didn't confuse you further.Just like @adetola said, they are both very important. The crank shaft will not rotate if the engine is not running and the engine will not run if the valves are not opening, the valves cannot open if the camshaft does not do it's work and finally, the cam shaft will not rotate if the crankshaft doesn't.
P.S. Dont judge a book by its cover