-er bbb bbc bbe bbl bbr bcb bcc bce bcl bcr be- beb bec bee bel ber blb blc ble bll blr brb bre brl brr c-- cbb cbc cbe cbl cbr ccb ccc cce ccl ccr ce- ceb cec cee cel cer cl- clb clc cle cll clr crb crc cre crl crr ebb ebc ebe ebl ebr ec- ecb ecc ece ecl ecr eeb eec eee eel eer elb elc ele ell elr erb erc ere erl err lbb lbc lbe lbl lbr lcb lcc lce lcl lcr leb lec lee lel ler llb llc lle lll llr lrb lrc lrr rbb rbc rbe rbl rbr rcb rcc rce rcl rcr re- reb rec ree rel rer rlc rle rll rlr rrb rrc rrl rrr