I worked for another 3 hours and am nearing the end of this marking

I worked for another three hours and am nearing the end of marking this test. At the moment I am too tired to continue to mark. I did manage to start a book on simulations and am just now installing a compiler, X code, for the Mac on my Macbook. But I realize I already have a G++ 4.0 compiler installed and can do the practice code from the C++ how to book using G++ I think. I will do some practice code from that book and try some simulations programming from the other book. But right now I am logging off and sleeping.