a-a a-b aaa aab aar aas aav ab- aba abb abr abs abv ar- ara arb arr ars arv as- asa asb asr ass asv av- ava avb avr avs baa bab bar bas bav bba bbb bbr bbs bra brb brr brs brv bsa bsb bsr bss bsv bva bvb bvr bvs bvv ra- raa rab rar ras rav rba rbb rbr rbs rra rrb rrr rrs rsa rsb rsr rss rsv rva rvb rvr rvs rvv saa sab sar sas sav sba sbb sbr sbs sbv sr- sra srb srr srs srv ss- ssa ssb ssr sss ssv sva svb svr svs svv v-a vaa vab var vas vav vba vbr vbs vbv vra vrb vrr vrs vsa vsb vsr vss vsv vva vvb vvr vvs vvv