a-a a-b a-c aaa aab aac aae aak aap aas ab- aba abb abc abe abk abp abs ac- aca acb acc ace ack acp acs aea aeb aec aee aek aep aes aka akb akc ake akk akp aks ap- apa apb apc ape apk app aps as- asa asb asc ase ask asp ass b-p baa bab bac bae bak bap bas bba bbb bbc bbe bbk bbp bbs bca bcb bcc bce bck bcp bcs be- bea beb bec bee bek bep bes bka bkb bkc bke bkk bkp bks bpa bpb bpc bpe bpp bps bsa bsb bsc bse bsk bsp bss c-- caa cab cac cae cak cap cas cba cbb cbc cbe cbk cbp cbs cca ccb ccc cce cck ccp ccs ce- cea ceb cec cee cek cep ces cka ckb ckc cks cpa cpb cpc cpe cpk cpp cps csa csb csc cse csk csp css eaa eab eac eae eak eap eas eba ebb ebc ebe ebk ebp ebs ec- eca ecb ecc ece eck ecs eea eeb eec eee eek eep ees eka ekb ekc eke ekp eks ep- epa epb epc epe epp eps es- esa esb esc ese esk esp ess ka- kaa kab kac kae kak kap kas kba kbb kbc kbe kbk kbp kbs kca kcb kcc kce kck kcp kcs ke- kea keb kec kee kek kep kes kkb kkc kke kkk kkp kks kpa kpc kpe kpk kpp kps ksa ksb ksc kse ksk ksp kss p-p paa pab pac pae pak pap pas pba pbb pbc pbe pbk pbp pbs pca pcb pcc pce pck pcp pcs pea peb pec pee pek pep pes pka pkb pkc pke pkp pks ppa ppb ppc ppe ppk ppp pps ps- psa psb psc pse psk psp pss saa sab sac sae sak sap sas sba sbb sbc sbe sbk sbp sbs sca scb scc sce sck scp scs se- sea seb sec see sek sep ses sk- ska skb skc ske skk skp sks spa spb spc spe spk spp sps ss- ssa ssb ssc sse ssk ssp sss