-al a-a a-b a-c aaa aab aac aad aae aaf aak aal ab- aba abb abc abd abe abf abk abl ac- aca acb acc acd ace acf ack acl ad- ada adb adc add ade adf adk adl aea aeb aec aed aee aef aek ael af- afa afb afc afd afe aff afk afl aka akb akc akd ake akk akl al- ala alb alc ald ale alf alk all baa bab bac bad bae baf bak bal bba bbb bbc bbd bbe bbf bbk bbl bca bcb bcc bcd bce bcf bck bcl bda bdb bdc bdd bde bdf bdk bdl be- bea beb bec bed bee bef bek bel bfa bfb bfc bfd bfe bff bfl bka bkb bkc bke bkf bkk bkl bla blb blc bld ble blf blk bll c-- caa cab cac cad cae caf cak cal cba cbb cbc cbd cbe cbf cbk cbl cca ccb ccc ccd cce ccf cck ccl cda cdb cdc cdd cde cdf cdk cdl ce- cea ceb cec ced cee cef cek cel cfa cfb cfc cfd cfe cff cfk cfl cka ckb ckc ckd cl- cla clb clc cld cle clf clk cll daa dab dac dad dae daf dak dal dba dbb dbc dbd dbe dbf dbk dbl dca dcb dcc dcd dce dcf dck dcl dda ddb ddc ddd dde ddf ddk ddl de- dea deb dec ded dee def dek del dfa dfb dfc dfd dfe dff dfk dfl dka dkb dkc dke dkk dkl dl- dla dlb dlc dld dle dlf dlk dll eaa eab eac ead eae eaf eak eal eba ebb ebc ebd ebe ebf ebk ebl ec- eca ecb ecc ecd ece ecf eck ecl ed- eda edb edc edd ede edf edk edl eea eeb eec eed eee eef eek eel ef- efa efb efc efd efe eff efl eka ekb ekc ekd eke ekf ekl ela elb elc eld ele elf elk ell faa fab fac fad fae faf fak fal fba fbb fbc fbd fbe fbf fbk fbl fca fcb fcc fcd fce fcf fck fcl fda fdb fdc fdd fde fdf fdk fdl fea feb fec fed fee fef fek fel ffa ffc ffd ffe fff ffk ffl fka fkb fkc fkf fkk fkl fla flb flc fld fle flf fll ka- kaa kab kac kad kae kaf kak kal kba kbb kbc kbd kbe kbf kbk kbl kca kcb kcc kcd kce kck kcl kda kdb kdc kde kdf kdk kdl ke- kea keb kec ked kee kef kek kel kfa kfc kfd kff kkb kkc kke kkk kkl kl- kla klb klc kld klf la- laa lab lac lad lae laf lak lal lba lbb lbc lbd lbe lbf lbk lbl lca lcb lcc lcd lce lcf lck lcl lda ldb ldc ldd lde ldf ldk ldl lea leb lec led lee lef lek lel lfa lfb lfc lfd lfe lff lfk lfl lka lkb lkl lla llb llc lld lle llf llk lll