a-a a-b aaa aab aam aao aau ab- aba abb abm abo abu ama amb amm amo amu aoa aob aom aoo aou au- aua aub aum auo b-u baa bab bam bao bau bba bbb bbm bbo bbu bma bmb bmm bmo bmu boa bob bom boo bou bua bub bum buo buu m-o maa mab mam mao mau mba mbb mbm mbo mbu mma mmb mmm mmo mmu moa mob mom moo mou mua mub mum muu oaa oab oam oao oau ob- oba obb obm obo obu om- oma omb omm omo omu oo- ooa oob oom ooo ou- oua oum ouo ua- uaa uab uam uao uau uba ubb ubo ubu um- uma umb umm umo umu uoa uob uom uoo uua uum uuu