a-a a-b a-c aaa aab aac aak aap aas aay ab- aba abb abc abk abp abs aby ac- aca acb acc ack acp acs acy aka akb akc akk akp aks ap- apa apb apc apk app aps apy as- asa asb asc ask asp ass asy ay- aya ayc ayk ayp ays b-p baa bab bac bak bap bas bay bba bbb bbc bbk bbp bbs bby bca bcb bcc bck bcp bcs bcy bka bkb bkc bkk bkp bks bpa bpb bpc bpp bps bpy bsa bsb bsc bsk bsp bss bsy by- bya byc byk byp bys c-- caa cab cac cak cap cas cay cba cbb cbc cbk cbp cbs cby cca ccb ccc cck ccp ccs cka ckb ckc cks cky cpa cpb cpc cpk cpp cps csa csb csc csk csp css csy cya cyb cyc cyk cyp cys ka- kaa kab kac kak kap kas kay kba kbb kbc kbk kbp kbs kca kcb kcc kck kcp kcs kkb kkc kkk kkp kks kky kpa kpc kpk kpp kps ksa ksb ksc ksk ksp kss kya kyc kyp kys p-p paa pab pac pak pap pas pay pba pbb pbc pbk pbp pbs pby pca pcb pcc pck pcp pcs pka pkb pkc pkp pks pky ppa ppb ppc ppk ppp pps ps- psa psb psc psk psp pss psy py- pya pyb pyc pyk pys saa sab sac sak sap sas say sba sbb sbc sbk sbp sbs sby sca scb scc sck scp scs sk- ska skb skc skk skp sks sky spa spb spc spk spp sps spy ss- ssa ssb ssc ssk ssp sss sy- sya syb syc syk syp sys yaa yab yac yak yap yas yay ybc ybp ybs yby yca ycc ycp ycs ycy yka ykk ypa yps ysa ysb ysc ysk ysp yss ysy yyb yyc yys yyy