-er -th bbb bbc bbe bbh bbr bbt bcb bcc bce bch bcr bct be- beb bec bee beh ber bet bhb bhc bhe bhh bhr bht brb bre brh brr brt btb btc bte bth btr btt c-- cbb cbc cbe cbh cbr cbt ccb ccc cce cch ccr cct ce- ceb cec cee ceh cer cet ch- chb chc che chh chr cht crb crc cre crh crr crt ctb ctc cte cth ctr ctt ebb ebc ebe ebh ebr ebt ec- ecb ecc ece ech ecr ect eeb eec eee eer eet ehb ehc ehe ehh ehr eht erb erc ere erh err ert etb etc ete eth etr ett hbb hbc hbe hbh hbr hbt hcb hcc hce hch hcr hct he- heb hec hee heh her het hhb hhc hhe hhh hhr hht hr- hrb hrc hre hrh hrr hrt htb htc hte hth htr htt rbb rbc rbe rbh rbr rbt rcb rcc rce rch rcr rct re- reb rec ree reh rer ret rh- rhb rhc rhe rhh rhr rht rrb rrc rrh rrr rrt rtb rtc rte rtr rtt tbb tbc tbe tbh tbr tbt tcb tcc tce tch tcr tct te- teb tec tee teh ter tet th- thb thc the thh thr tht trb trc tre trh trr trt ttb ttc tte tth ttr ttt