Let me bring you a glass of Nighon wine for your efforts, milady, and as you gently taste its bounty, request one small additional item to be added... a brief explanation, if I may be so bold...
It looks like you need to do something at Xn to access the area at n... is that right? Would it be possible to add that little instruction at the beginning, for those unworthy souls such as my own which are certainly challenged when it comes to interpretation and reading of minds...
Great stuff!