a-a a-b a-c aaa aab aac aad aae aak aas ab- aba abb abc abd abe abk abs ac- aca acb acc acd ace ack acs ad- ada adb adc add ade adk ads aea aeb aec aed aee aek aes aka akb akc akd ake akk aks as- asa asb asc asd ase ask ass baa bab bac bad bae bak bas bba bbb bbc bbd bbe bbk bbs bca bcb bcc bcd bce bck bcs bda bdb bdc bdd bde bdk bds be- bea beb bec bed bee bek bes bka bkb bkc bke bkk bks bsa bsb bsc bsd bse bsk bss c-- caa cab cac cad cae cak cas cba cbb cbc cbd cbe cbk cbs cca ccb ccc ccd cce cck ccs cda cdb cdc cdd cde cdk cds ce- cea ceb cec ced cee cek ces cka ckb ckc ckd cks csa csb csc csd cse csk css daa dab dac dad dae dak das dba dbb dbc dbd dbe dbk dbs dca dcb dcc dcd dce dck dcs dda ddb ddc ddd dde ddk dds de- dea deb dec ded dee dek des dka dkb dkc dke dkk dks dsa dsb dsc dsd dse dsk dss eaa eab eac ead eae eak eas eba ebb ebc ebd ebe ebk ebs ec- eca ecb ecc ecd ece eck ecs ed- eda edb edc edd ede edk eds eea eeb eec eed eee eek ees eka ekb ekc ekd eke eks es- esa esb esc esd ese esk ess ka- kaa kab kac kad kae kak kas kba kbb kbc kbd kbe kbk kbs kca kcb kcc kcd kce kck kcs kda kdb kdc kde kdk kds ke- kea keb kec ked kee kek kes kkb kkc kke kkk kks ksa ksb ksc ksd kse ksk kss saa sab sac sad sae sak sas sba sbb sbc sbd sbe sbk sbs sca scb scc scd sce sck scs sda sdb sdc sdd sde sdk sds se- sea seb sec sed see sek ses sk- ska skb skc skd ske skk sks ss- ssa ssb ssc ssd sse ssk sss