-ol bbb bbc bbe bbg bbl bbo bcb bcc bce bcg bcl bco be- beb bec bee beg bel beo bgb bgc bge bgg bgl bgo blb blc ble blg bll blo bob boc boe bog bol boo c-- cbb cbc cbe cbg cbl cbo ccb ccc cce ccg ccl cco ce- ceb cec cee ceg cel ceo cgb cgc cge cgg cgl cgo cl- clb clc cle clg cll clo co- cob coc coe cog col coo ebb ebc ebe ebg ebl ebo ec- ecb ecc ece ecg ecl eco eeb eec eee eeg eel eeo egb egc ege egg egl ego elb elc ele elg ell elo eo- eob eoc eoe eog eol eoo gbc gbe gbg gbl gbo gcb gcc gce gcg gcl gco ge- geb gec gee geg gel geo ggb ggc ggg ggo glb glc gle glg gll glo gob goc goe gog gol goo lbb lbc lbe lbg lbl lbo lcb lcc lce lcg lcl lco leb lec lee leg lel leo lgb lgc lge lgg lgl lgo llb llc lle llg lll llo lob loc loe log lol loo ob- obb obc obe obg obl obo oc- ocb occ ocg ocl oco oeb oec oee oeg oel oeo ogc oge ogg ogl ogo olb olc ole olg oll olo oo- oob ooc oog ool ooo