-ic a-a a-b a-c a-i aaa aab aac aaf aai aas aay ab- aba abb abc abf abi abs aby ac- aca acb acc acf aci acs acy af- afa afb afc aff afi afs afy ai- aia aib aic aif aii ais aiy as- asa asb asc asf asi ass asy ay- aya ayc ayf ayi ays baa bab bac baf bai bas bay bba bbb bbc bbf bbi bbs bby bca bcb bcc bcf bci bcs bcy bfa bfb bfc bff bfi bfs bfy bi- bia bib bic bif bii bis biy bsa bsb bsc bsf bsi bss bsy by- bya byc byf byi bys c-- caa cab cac caf cai cas cay cba cbb cbc cbf cbi cbs cby cca ccb ccc ccf cci ccs cfa cfb cfc cff cfi cfs ci- cia cib cic cif cii cis csa csb csc csf csi css csy cya cyb cyc cyf cys faa fab fac faf fai fas fay fba fbb fbc fbf fbi fbs fca fcb fcc fcf fci fcs fcy ffa ffc fff ffi ffs ffy fia fib fic fif fii fis fsa fsb fsc fsf fsi fss fy- fya fyb fyc fyi i-f ia- iaa iab iac iaf iai ias iba ibb ibc ibf ibi ibs iby ica icb icc icf ici ics icy ifa ifb ifc iff ifi ifs ify iia iib iic iif iii iis is- isa isb isc isf isi iss isy iya iyc iys iyy saa sab sac saf sai sas say sba sbb sbc sbf sbi sbs sby sca scb scc scf sci scs sfa sfb sfc sff sfi sfs sia sib sic sif sii sis ss- ssa ssb ssc ssf ssi sss sy- sya syb syc syi sys yaa yab yac yaf yai yas yay ybc ybf ybi ybs yby yca ycc ycf yci ycs ycy yfa yfc yff yfs yif yii yis ysa ysb ysc ysi yss ysy yyb yyc yyf yys yyy