a-a a-b a-c aaa aab aac aad aah ab- aba abb abc abd abh ac- aca acb acc acd ach ad- ada adb adc add adh aha ahb ahc ahd ahh baa bab bac bad bah bba bbb bbc bbd bbh bca bcb bcc bcd bch bda bdb bdc bdd bdh bha bhb bhc bhd bhh c-- caa cab cac cad cah cba cbb cbc cbd cbh cca ccb ccc ccd cch cda cdb cdc cdd cdh ch- cha chb chc chd chh daa dab dac dad dah dba dbb dbc dbd dbh dca dcb dcc dcd dda ddb ddc ddd ddh dh- dha dhb dhc dhd dhh haa hab hac had hah hba hbb hbc hbd hbh hca hcb hcc hcd hch hda hdb hdc hdd hdh hha hhb hhc hhd hhh