a-a a-b aaa aab aaj aan aao ab- aba abb abj abn abo aja ajb ajj ajn ajo an- ana anb anj ann ano aoa aob aoj aon aoo baa bab baj ban bao bba bbb bbn bbo bja bjj bjn bna bnb bnj bnn bno boa bob boj bon boo jaa jab jaj jan jao jba jbj jbo jja jjb jjj jna jnj jnn jno joa job joj jon joo naa nab naj nan nao nba nbb nbn nbo nja njn nna nnb nnn nno no- noa nob noj non noo oaa oab oaj oan oao ob- oba obb obj obn obo oja ojb ojo on- ona onb onj onn ono oo- ooa oob oon ooo