a-a a-b a-c aaa aab aac aap aar aas aay ab- aba abb abc abp abr abs aby ac- aca acb acc acp acr acs acy ap- apa apb apc app apr aps apy ar- ara arb arc arp arr ars ary as- asa asb asc asp asr ass asy ay- aya ayc ayp ayr ays b-p baa bab bac bap bar bas bay bba bbb bbc bbp bbr bbs bby bca bcb bcc bcp bcr bcs bcy bpa bpb bpc bpp bpr bps bpy bra brb brp brr brs bry bsa bsb bsc bsp bsr bss bsy by- bya byc byp byr bys c-- caa cab cac cap car cas cay cba cbb cbc cbp cbr cbs cby cca ccb ccc ccp ccr ccs cpa cpb cpc cpp cpr cps cra crb crc crp crr crs cry csa csb csc csp csr css csy cya cyb cyc cyp cyr cys p-p paa pab pac pap par pas pay pba pbb pbc pbp pbr pbs pby pca pcb pcc pcp pcr pcs ppa ppb ppc ppp ppr pps pra prb prc prp prr prs pry ps- psa psb psc psp psr pss psy py- pya pyb pyc pyr pys ra- raa rab rac rap rar ras ray rba rbb rbc rbp rbr rbs rca rcb rcc rcp rcr rcs rpa rpb rpc rpp rpr rps rra rrb rrc rrp rrr rrs rsa rsb rsc rsp rsr rss ry- rya ryc ryr rys ryy saa sab sac sap sar sas say sba sbb sbc sbp sbr sbs sby sca scb scc scp scr scs spa spb spc spp spr sps spy sr- sra srb src srp srr srs sry ss- ssa ssb ssc ssp ssr sss sy- sya syb syc syp syr sys yaa yab yac yap yar yas yay ybc ybp ybr ybs yby yca ycc ycp ycs ycy ypa yps yra yrc yrp yrs ysa ysb ysc ysp ysr yss ysy yyb yyc yys yyy