a-a a-b a-i aaa aab aai aao aas aav ab- aba abb abi abo abs abv ai- aia aib aii aio ais aiv aoa aob aoi aoo aos aov as- asa asb asi aso ass asv av- ava avb avi avo avs baa bab bai bao bas bav bba bbb bbi bbo bbs bi- bia bib bii bio bis biv boa bob boi boo bos bov bsa bsb bsi bso bss bsv bva bvb bvi bvo bvs bvv i-v ia- iaa iab iai iao ias iav iba ibb ibi ibo ibs ibv iia iib iii iio iis io- ioa iob ioi ioo ios iov is- isa isb isi iso iss isv iva ivb ivi ivo ivs ivv o-i oaa oab oai oao oas oav ob- oba obb obi obo obs obv oia oib oii oio ois oiv oo- ooa oob ooi ooo oos oov os- osa osb osi oso oss osv ov- ova ovb ovi ovo ovs ovv saa sab sai sao sas sav sba sbb sbi sbo sbs sbv sia sib sii sio sis siv soa sob soi soo sos sov ss- ssa ssb ssi sso sss ssv sva svb svi svo svs svv v-a vaa vab vai vao vas vav vba vbi vbo vbs vbv vi- via vib vii vio vis viv voa vob voi voo vos vov vsa vsb vsi vso vss vsv vva vvb vvi vvo vvs vvv