a-a a-b a-i aaa aab aag aai aav ab- aba abb abg abi abv ag- aga agb agg agi agv ai- aia aib aig aii aiv av- ava avb avg avi baa bab bag bai bav bba bbb bbg bbi bga bgb bgg bgi bgv bi- bia bib big bii biv bva bvb bvg bvi bvv gaa gab gag gai gav gba gbg gbi gbv gga ggb ggg ggi ggv gia gib gig gii giv gva gvb gvg gvi i-v ia- iaa iab iag iai iav iba ibb ibg ibi ibv iga igb igg igi iia iib iii iva ivb ivg ivi ivv v-a vaa vab vag vai vav vba vbg vbi vbv vga vgg vi- via vib vig vii viv vva vvb vvg vvi vvv