Seeing FB has given it away, the answer is 6.
I also could only see 3 and nearly every other person I know can only see 3 or 4.
Apparently the brain cannot process 'OF'.
Anyone who counts all 6 'F's' on the first go is a genius, so we have a couple of those here by looks.
Hehehe. Sorry Dell. People are still more likely to read the first post and try it before they read mine. or yours. Just brings the honesty factor in a bit more.
I don't think it shows you're a genius really. Might show that you read slower yet more carefully.