a-a a-b a-c aaa aab aac aad aao aau aav ab- aba abb abc abd abo abu abv ac- aca acb acc acd aco acu acv ad- ada adb adc add ado adu adv aoa aob aoc aod aoo aou aov au- aua aub auc aud auo auv av- ava avb avc avd avo avu b-u baa bab bac bad bao bau bav bba bbb bbc bbd bbo bbu bca bcb bcc bcd bco bcu bcv bda bdb bdc bdd bdo bdu bdv boa bob boc bod boo bou bov bua bub buc bud buo buu bva bvb bvc bvd bvo bvu bvv c-- caa cab cac cad cao cau cav cba cbb cbc cbd cbo cbu cbv cca ccb ccc ccd cco ccu ccv cda cdb cdc cdd cdo cdu cdv co- coa cob coc cod coo cou cov cua cub cuc cud cuo cuu cuv cva cvb cvc cvd cvo cvu cvv daa dab dac dad dao dau dav dba dbb dbc dbd dbo dbu dbv dca dcb dcc dcd dco dcu dcv dda ddb ddc ddd ddo ddu doa dob doc dod doo dou dov dua dub duc dud duo duv dva dvb dvc dvd dvu oaa oab oac oad oao oau oav ob- oba obb obc obd obo obu obv oc- oca ocb occ ocd oco ocu ocv oda odb odc odd odo odu odv oo- ooa oob ooc ood ooo oov ou- oua ouc oud ouo ov- ova ovb ovc ovd ovo ovv ua- uaa uab uac uad uao uau uav uba ubb ubc ubo ubu ubv uca ucb ucc ucd uco ucu ucv uda udb udc udd udo udu udv uoa uob uoc uod uoo uua uuc uuu uva uvb uvc uvo uvu uvv v-a vaa vab vac vad vao vau vav vba vbc vbd vbo vbv vca vcc vcd vco vcu vdb vdc vdd vdo vdu vdv voa vob voc vod voo vou vov vuv vva vvb vvc vvo vvv