a-a a-b a-c aaa aab aac aad aah aar ab- aba abb abc abd abh abr ac- aca acb acc acd ach acr ad- ada adb adc add adh adr aha ahb ahc ahd ahh ahr ar- ara arb arc ard arh arr baa bab bac bad bah bar bba bbb bbc bbd bbh bbr bca bcb bcc bcd bch bcr bda bdb bdc bdd bdh bdr bha bhb bhc bhd bhh bhr bra brb brd brh brr c-- caa cab cac cad cah car cba cbb cbc cbd cbh cbr cca ccb ccc ccd cch ccr cda cdb cdc cdd cdh cdr ch- cha chb chc chd chh chr cra crb crc crd crh crr daa dab dac dad dah dar dba dbb dbc dbd dbh dbr dca dcb dcc dcd dcr dda ddb ddc ddd ddh ddr dh- dha dhb dhc dhd dhh dhr dra drb drc drd drr haa hab hac had hah har hba hbb hbc hbd hbh hbr hca hcb hcc hcd hch hcr hda hdb hdc hdd hdh hdr hha hhb hhc hhd hhh hhr hr- hra hrb hrc hrd hrh hrr ra- raa rab rac rad rah rar rba rbb rbc rbd rbh rbr rca rcb rcc rcd rch rcr rda rdb rdc rdd rdh rdr rh- rha rhb rhc rhd rhh rhr rra rrb rrc rrd rrh rrr