a-a a-c a-z aaa aac aad aar aax aaz ac- aca acc acd acr acx acz ad- ada adc add adr adx adz ar- ara arc ard arr arx arz ax- axa axr axx az- aza azd azx azz c-- caa cac cad car cax caz cca ccc ccd ccr ccx ccz cda cdc cdd cdr cdx cdz cra crc crd crr crx crz cxc cxr cxx cz- czc czd daa dac dad dar dax daz dca dcc dcd dcr dcx dda ddc ddd ddr ddx ddz dra drc drd drr drx drz dxc dxd dxr dxx dza dzd dzr ra- raa rac rad rar rax raz rca rcc rcd rcr rcx rda rdc rdd rdr rdx rra rrc rrd rrr rxr rza xaa xac xad xar xcd xcr xcx xda xdc xdr xrc xrd xrx xxx zaa zac zad zar zax zaz zxx zzr zzx zzz