-er a-a a-b a-q aaa aab aae aan aaq aar ab- aba abb abe abn abq abr aea aeb aee aen aeq aer an- ana anb ane ann anq anr aqa aqn aqr ar- ara arb are arn arq arr baa bab bae ban baq bar bba bbb bbe bbn bbq bbr be- bea beb bee ben beq ber bna bnb bne bnn bnr bqe bra brb bre brn brq brr eaa eab eae ean ear eba ebb ebe ebn ebq ebr eea eeb eee een eer en- ena enb ene enn enr eqa eqe eqn eqq era erb ere ern erq err naa nab nae nan nar nba nbb nbe nbn nbr ne- nea neb nee nen ner nna nnb nne nnn nra nrb nre nrn nrr qaa qan qar qba qbe qbq qee qen qnb qne qqq qra qrb qre ra- raa rab rae ran raq rar rba rbb rbe rbn rbr re- rea reb ree ren req rer rna rnb rnn rnr rqn rra rrb rrn rrq rrr