-er a-a a-b aaa aab aae aak aam aan aar ab- aba abb abe abk abm abn abr aea aeb aee aek aem aen aer aka akb ake akk akm akn akr ama amb ame amk amm amn amr an- ana anb ane ank anm ann anr ar- ara arb are ark arm arn arr baa bab bae bak bam ban bar bba bbb bbe bbk bbm bbn bbr be- bea beb bee bek bem ben ber bka bkb bke bkk bkm bkn bkr bma bmb bme bmk bmm bmn bmr bna bnb bne bnk bnn bnr bra brb bre brk brm brn brr eaa eab eae eak eam ean ear eba ebb ebe ebk ebm ebn ebr eea eeb eee eek eem een eer eka ekb eke ekr em- ema emb eme emk emm emn emr en- ena enb ene enk enm enn enr era erb ere erk erm ern err ka- kaa kab kae kak kam kan kar kba kbb kbe kbk kbm kbn kbr ke- kea keb kee kek kem ken ker kkb kke kkk kkm kkn kkr kma kmb kme kmk kmm kn- kna kne knk knm knn knr kra krk krn krr m-r maa mab mae mak mam man mar mba mbb mbe mbk mbm mbr mea meb mee mek mem men mer mka mkb mke mkk mkm mkn mkr mma mmb mme mmk mmm mmn mmr mna mnb mne mnk mnm mnn mnr mra mrb mre mrk mrm mrn mrr naa nab nae nak nam nan nar nba nbb nbe nbk nbm nbn nbr ne- nea neb nee nek nem nen ner nka nke nkk nkm nkn nkr nma nmb nme nmk nmm nmn nmr nna nnb nne nnk nnm nnn nra nrb nre nrk nrm nrn nrr ra- raa rab rae rak ram ran rar rba rbb rbe rbk rbm rbn rbr re- rea reb ree rek rem ren rer rkb rke rkk rkm rma rmb rme rmm rmn rmr rna rnb rnm rnn rnr rra rrb rrk rrm rrn rrr