-er bbb bbc bbe bbf bbl bbr bbt bcb bcc bce bcf bcl bcr bct be- beb bec bee bef bel ber bet bfb bfc bfe bff bfl bfr bft blb blc ble blf bll blr blt brb bre brf brl brr brt btb btc bte btf btl btr btt c-- cbb cbc cbe cbf cbl cbr cbt ccb ccc cce ccf ccl ccr cct ce- ceb cec cee cef cel cer cet cfb cfc cfe cff cfl cfr cft cl- clb clc cle clf cll clr clt crb crc cre crf crl crr crt ctb ctc cte ctf ctl ctr ctt ebb ebc ebe ebf ebl ebr ebt ec- ecb ecc ece ecf ecl ecr ect eeb eec eee eef eel eer eet ef- efb efc efe eff efl efr eft elb elc ele elf ell elr elt erb erc ere erf erl err ert etb etc ete etf etl etr ett fbb fbc fbe fbf fbl fbr fbt fcb fcc fce fcf fcl fcr fct feb fec fee fef fel fer fet ffc ffe fff ffl ffr fft flb flc fle flf fll flr flt frb frc fre frf frl frr frt ftb ftc fte ftf ftl ftr ftt lbb lbc lbe lbf lbl lbr lbt lcb lcc lce lcf lcl lcr lct leb lec lee lef lel ler let lfb lfc lfe lff lfl lfr lft llb llc lle llf lll llr llt lrb lrc lrf lrr lrt ltb ltc lte ltf ltl ltr ltt rbb rbc rbe rbf rbl rbr rbt rcb rcc rce rcf rcl rcr rct re- reb rec ree ref rel rer ret rfb rfc rfe rff rfl rfr rft rlc rle rlf rll rlr rlt rrb rrc rrf rrl rrr rrt rtb rtc rte rtf rtl rtr rtt tbb tbc tbe tbf tbl tbr tbt tcb tcc tce tcf tcl tcr tct te- teb tec tee tef tel ter tet tfb tfc tfe tff tfl tfr tft tlc tle tlf tll tlr tlt trb trc tre trf trl trr trt ttb ttc tte ttf ttl ttr ttt