bbb bbc bbd bbe bbk bbl bcb bcc bcd bce bck bcl bdb bdc bdd bde bdk bdl be- beb bec bed bee bek bel bkb bkc bke bkk bkl blb blc bld ble blk bll c-- cbb cbc cbd cbe cbk cbl ccb ccc ccd cce cck ccl cdb cdc cdd cde cdk cdl ce- ceb cec ced cee cek cel ckb ckc ckd cl- clb clc cld cle clk cll dbb dbc dbd dbe dbk dbl dcb dcc dcd dce dck dcl ddb ddc ddd dde ddk ddl de- deb dec ded dee dek del dkb dkc dke dkk dkl dl- dlb dlc dld dle dlk dll ebb ebc ebd ebe ebk ebl ec- ecb ecc ecd ece eck ecl ed- edb edc edd ede edk edl eeb eec eed eee eek eel ekb ekc ekd eke ekl elb elc eld ele elk ell kbb kbc kbd kbe kbk kbl kcb kcc kcd kce kck kcl kdb kdc kde kdk kdl ke- keb kec ked kee kek kel kkb kkc kke kkk kkl kl- klb klc kld lbb lbc lbd lbe lbk lbl lcb lcc lcd lce lck lcl ldb ldc ldd lde ldk ldl leb lec led lee lek lel lkb lkl llb llc lld lle llk lll