Your choice for words is the problem. Read your post again. I am talking about the words "of course." Example, if I walk into a dentist office and the doctor tells me that I have two cavities and I reply OF COURSE I KNOW WHAT A CAVITY IS, DOCTOR. This is a disrespectful reply.There was no disrespect aimed at Mark. I was looking at the solution itself, apart from Mark suggesting it. Anyway, I knew the answers beforehand, but I posted the problem to see if other people knew.