bbb bbc bbd bbe bbl bcb bcc bcd bce bcl bdb bdc bdd bde bdl be- beb bec bed bee bel blb blc bld ble bll c-- cbb cbc cbd cbe cbl ccb ccc ccd cce ccl cdb cdc cdd cde cdl ce- ceb cec ced cee cel cl- clb clc cld cle cll dbb dbc dbd dbe dbl dcb dcc dcd dce dcl ddb ddc ddd dde ddl de- deb dec ded dee del dl- dlb dlc dld dle dll ebb ebc ebd ebe ebl ec- ecb ecc ecd ece ecl ed- edb edc edd ede edl eeb eec eed eee eel elb elc eld ele ell lbb lbc lbd lbe lbl lcb lcc lcd lce lcl ldb ldc ldd lde ldl leb lec led lee lel llb llc lld lle lll