a-a a-b a-i aaa aab aai aao aav ab- aba abb abi abo abv ai- aia aib aii aio aiv aoa aob aoi aoo aov av- ava avb avi avo baa bab bai bao bav bba bbb bbi bbo bi- bia bib bii bio biv boa bob boi boo bov bva bvb bvi bvo bvv i-v ia- iaa iab iai iao iav iba ibb ibi ibo ibv iia iib iii iio io- ioa iob ioi ioo iov iva ivb ivi ivo ivv o-i oaa oab oai oao oav ob- oba obb obi obo obv oia oib oii oio oiv oo- ooa oob ooi ooo oov ov- ova ovb ovi ovo ovv v-a vaa vab vai vao vav vba vbi vbo vbv vi- via vib vii vio viv voa vob voi voo vov vva vvb vvi vvo vvv