a-a a-i a-z aaa aaf aai aar aax aay aaz af- afa aff afi afr afx afy afz ai- aia aif aii air aix aiy aiz ar- ara arf ari arr arx ary arz ax- axa axi axr axx ay- aya ayf ayi ayr ayx ayz az- aza azf azi azx azy azz faa faf fai far fax fay faz ffa fff ffi ffr ffx ffy ffz fia fif fii fir fix fiz fra frf fri frr fry fxi fxr fxx fy- fya fyi fyz i-f ia- iaa iaf iai iar iaz ifa iff ifi ifr ifx ify ifz iia iif iii iir iix ir- ira irf iri irr irx iry ixi ixy iya iyr iyy iza izi izy izz ra- raa raf rai rar rax ray raz rfa rff rfi rfr rfz ria rif rii rir rix riy riz rra rrf rri rrr rxr ry- rya ryf ryr ryy ryz rza rzy xaa xaf xar xfa xfx xia xii xix xrf xrx xry xxi xxx xxy xyr xyy xyz yaa yaf yai yar yax yay yaz yfa yff yfr yif yii yir yiz yra yrf yxa yxy yyf yyy yyz yzf yzr yzy zaa zaf zai zar zax zay zaz zfa zfr zfx zfy zia zif zir zix ziz zxx zyx zzr zzx zzy zzz