a-a a-c aaa aac aao aar aav aax ac- aca acc aco acr acv acx aoa aoc aoo aor aov aox ar- ara arc aro arr arv arx av- ava avc avo avr avx ax- axa axo axr axv axx c-- caa cac cao car cav cax cca ccc cco ccr ccv ccx co- coa coc coo cor cov cox cra crc cro crr crv crx cva cvc cvo cvr cvv cvx cxc cxo cxr cxv cxx oaa oac oao oar oav oax oc- oca occ oco ocr ocv ocx oo- ooa ooc ooo oor oov oox or- ora orc oro orr orv orx ov- ova ovc ovo ovv ox- oxa oxc oxo oxx ra- raa rac rao rar rav rax rca rcc rco rcr rcv rcx roa roc roo ror rov rox rra rrc rrr rva rvc rvo rvr rvv rxr v-a vaa vac vao var vav vax vca vcc vco vcr vcx voa voc voo vor vov vox vra vrc vrr vva vvc vvo vvr vvv vxa vxr vxv xaa xac xar xav xcr xcv xcx xoa xoc xoo xor xov xox xrc xrx xxo xxv xxx