0 - 0 - 0- 0 - 0 - 0- 0 - 0 - 0- 0 - 0 - 0- r - r - r- r - r - r- w - w - w- w a-a-p o f 0 d s [0a]-f [0d] s [0a]-f [0d] f d [0s] a 0 f d [0a]-f [0d] a 0 o f [0d] f d [0s] a r f d [rp]-f [rd] p r o o [ro] p a [ra]po w f d [wa]-f [wd] p w a---- [0f]fa a [0a]ad p [0p]pp [0d] p pp[0p] d-0- [0f]ffff [0a]aaad [0a]aaa [0d] aaaa[0a] d-0- [rf]fa a [ra]ad p [rp]pd [rp] pppp[rd] a-r- [wf]ffff [wa]aaad waaa [wa] aaaaf f d