a-a a-b a-c aaa aab aac aad aah aan ab- aba abb abc abd abh abn ac- aca acb acc acd ach acn ad- ada adb adc add adh adn aha ahb ahc ahd ahh ahn an- ana anb anc and anh ann baa bab bac bad bah ban bba bbb bbc bbd bbh bbn bca bcb bcc bcd bch bcn bda bdb bdc bdd bdh bha bhb bhc bhd bhh bna bnb bnc bnd bnn c-- caa cab cac cad cah can cba cbb cbc cbd cbh cbn cca ccb ccc ccd cch ccn cda cdb cdc cdd cdh cdn ch- cha chb chc chd chh chn cn- cna cnb cnc cnd cnh cnn daa dab dac dad dah dan dba dbb dbc dbd dbh dbn dca dcb dcc dcd dcn dda ddb ddc ddd ddh ddn dh- dha dhb dhc dhd dhh dna dnb dnc dnd dnh dnn haa hab hac had hah han hba hbb hbc hbd hbh hbn hca hcb hcc hcd hch hcn hda hdb hdc hdd hdh hdn hha hhb hhc hhd hhh hhn hna hnb hnc hnd hnh hnn naa nab nac nad nah nan nba nbb nbc nbd nbn nca ncb ncc ncd nch ncn nda ndb ndc ndd ndh ndn nha nhb nhc nhd nhh nhn nna nnb nnc nnh nnn