a-a a-b aaa aab aae aak aap aas ab- aba abb abe abk abp abs aea aeb aee aek aep aes aka akb ake akk akp aks ap- apa apb ape apk app aps as- asa asb ase ask asp ass b-p baa bab bae bak bap bas bba bbb bbe bbk bbp bbs be- bea beb bee bek bep bes bka bkb bke bkk bkp bks bpa bpb bpe bpp bps bsa bsb bse bsk bsp bss eaa eab eae eak eap eas eba ebb ebe ebk ebp ebs eea eeb eee eek eep ees eka ekb eke ekp eks ep- epa epb epe epp eps es- esa esb ese esk esp ess ka- kaa kab kae kak kap kas kba kbb kbe kbk kbp kbs ke- kea keb kee kek kep kes kkb kke kkk kkp kks kpa kpe kpk kpp kps ksa ksb kse ksk ksp kss p-p paa pab pae pak pap pas pba pbb pbe pbk pbp pbs pea peb pee pek pep pes pka pkb pke pkp pks ppa ppb ppe ppk ppp pps ps- psa psb pse psk psp pss saa sab sae sak sap sas sba sbb sbe sbk sbp sbs se- sea seb see sek sep ses sk- ska skb ske skk skp sks spa spb spe spk spp sps ss- ssa ssb sse ssk ssp sss