bbb bbc bbe bbk bbl bbm bcb bcc bce bck bcl bcm be- beb bec bee bek bel bem bkb bkc bke bkk bkl bkm blb blc ble blk bll blm bmb bmc bme bmk bml bmm c-- cbb cbc cbe cbk cbl cbm ccb ccc cce cck ccl ccm ce- ceb cec cee cek cel cem ckb ckc ckm cl- clb clc cle clk cll clm cmb cmc cme cmk cml cmm ebb ebc ebe ebk ebl ebm ec- ecb ecc ece eck ecl ecm eeb eec eee eek eel eem ekb ekc eke ekl elb elc ele elk ell elm em- emb emc eme emk eml emm kbb kbc kbe kbk kbl kbm kcb kcc kce kck kcl kcm ke- keb kec kee kek kel kem kkb kkc kke kkk kkl kkm kl- klb klc klm kmb kmc kme kmk kml kmm lbb lbc lbe lbk lbl lbm lcb lcc lce lck lcl lcm leb lec lee lek lel lem lkb lkl llb llc lle llk lll llm lmb lmc lme lmk lml lmm mbb mbc mbe mbk mbl mbm mc- mcb mcc mce mck mcl mcm meb mec mee mek mel mem mkb mkc mke mkk mkl mkm mlb mlc mle mlk mll mlm mmb mmc mme mmk mml mmm