a-a a-b aaa aab aad aao aar aas aav ab- aba abb abd abo abr abs abv ad- ada adb add ado adr ads adv aoa aob aod aoo aor aos aov ar- ara arb ard aro arr ars arv as- asa asb asd aso asr ass asv av- ava avb avd avo avr avs baa bab bad bao bar bas bav bba bbb bbd bbo bbr bbs bda bdb bdd bdo bdr bds bdv boa bob bod boo bor bos bov bra brb brd bro brr brs brv bsa bsb bsd bso bsr bss bsv bva bvb bvd bvo bvr bvs bvv daa dab dad dao dar das dav dba dbb dbd dbo dbr dbs dbv dda ddb ddd ddo ddr dds doa dob dod doo dor dos dov dra drb drd dro drr drs drv dsa dsb dsd dso dsr dss dsv dva dvb dvd dvr dvs oaa oab oad oao oar oas oav ob- oba obb obd obo obr obs obv oda odb odd odo odr ods odv oo- ooa oob ood ooo oor oos oov or- ora orb ord oro orr ors orv os- osa osb osd oso osr oss osv ov- ova ovb ovd ovo ovs ovv ra- raa rab rad rao rar ras rav rba rbb rbd rbo rbr rbs rda rdb rdd rdo rdr rds rdv roa rob rod roo ror ros rov rra rrb rrd rrr rrs rsa rsb rsd rso rsr rss rsv rva rvb rvd rvo rvr rvs rvv saa sab sad sao sar sas sav sba sbb sbd sbo sbr sbs sbv sda sdb sdd sdo sdr sds sdv soa sob sod soo sor sos sov sr- sra srb srd sro srr srs srv ss- ssa ssb ssd sso ssr sss ssv sva svb svd svo svr svs svv v-a vaa vab vad vao var vas vav vba vbd vbo vbr vbs vbv vdb vdd vdo vdr vds vdv voa vob vod voo vor vos vov vra vrb vrd vrr vrs vsa vsb vsd vso vsr vss vsv vva vvb vvo vvr vvs vvv