a-a a-b a-c aaa aab aac aag aao aar aav ab- aba abb abc abg abo abr abv ac- aca acb acc acg aco acr acv ag- aga agb agc agg ago agr agv aoa aob aoc aog aoo aor aov ar- ara arb arc arg aro arr arv av- ava avb avc avg avo avr baa bab bac bag bao bar bav bba bbb bbc bbg bbo bbr bca bcb bcc bcg bco bcr bcv bga bgb bgc bgg bgo bgr bgv boa bob boc bog boo bor bov bra brb brg bro brr brv bva bvb bvc bvg bvo bvr bvv c-- caa cab cac cag cao car cav cba cbb cbc cbg cbo cbr cbv cca ccb ccc ccg cco ccr ccv cga cgb cgc cgg cgo cgr cgv co- coa cob coc cog coo cor cov cra crb crc crg cro crr crv cva cvb cvc cvg cvo cvr cvv gaa gab gac gag gao gar gav gba gbc gbg gbo gbr gbv gca gcb gcc gcg gco gcr gga ggb ggc ggg ggo ggr ggv goa gob goc gog goo gor gov gra grb grc grg gro grr grv gva gvb gvc gvg gvo gvr oaa oab oac oag oao oar oav ob- oba obb obc obg obo obr obv oc- oca ocb occ ocg oco ocr ocv oga ogc ogg ogo oo- ooa oob ooc oog ooo oor oov or- ora orb orc org oro orr orv ov- ova ovb ovc ovo ovv ra- raa rab rac rag rao rar rav rba rbb rbc rbg rbo rbr rca rcb rcc rcg rco rcr rcv rga rgb rgc rgg rgo rgr rgv roa rob roc rog roo ror rov rra rrb rrc rrg rrr rva rvb rvc rvg rvo rvr rvv v-a vaa vab vac vag vao var vav vba vbc vbg vbo vbr vbv vca vcc vco vcr vga vgc vgg vgo vgr voa vob voc vog voo vor vov vra vrb vrc vrg vrr vva vvb vvc vvg vvo vvr vvv