-ey a-a a-b a-c aaa aab aac aad aae aaf aay ab- aba abb abc abd abe abf aby ac- aca acb acc acd ace acf acy ad- ada adb adc add ade adf ady aea aeb aec aed aee aef aey af- afa afb afc afd afe aff afy ay- aya ayc ayd aye ayf baa bab bac bad bae baf bay bba bbb bbc bbd bbe bbf bby bca bcb bcc bcd bce bcf bcy bda bdb bdc bdd bde bdf bdy be- bea beb bec bed bee bef bey bfa bfb bfc bfd bfe bff bfy by- bya byc byd bye byf c-- caa cab cac cad cae caf cay cba cbb cbc cbd cbe cbf cby cca ccb ccc ccd cce ccf cda cdb cdc cdd cde cdf cdy ce- cea ceb cec ced cee cef cey cfa cfb cfc cfd cfe cff cya cyb cyc cyd cye cyf daa dab dac dad dae daf day dba dbb dbc dbd dbe dbf dby dca dcb dcc dcd dce dcf dda ddb ddc ddd dde ddf ddy de- dea deb dec ded dee def dey dfa dfb dfc dfd dfe dff dy- dya dyb dyc dyd dye dyy eaa eab eac ead eae eaf eba ebb ebc ebd ebe ebf eby ec- eca ecb ecc ecd ece ecf ed- eda edb edc edd ede edf edy eea eeb eec eed eee eef eey ef- efa efb efc efd efe eff eya eyc eyd eye faa fab fac fad fae faf fay fba fbb fbc fbd fbe fbf fca fcb fcc fcd fce fcf fcy fda fdb fdc fdd fde fdf fea feb fec fed fee fef fey ffa ffc ffd ffe fff ffy fy- fya fyb fyc fye yaa yab yac yad yae yaf yay ybc ybe ybf yby yca ycc ycd yce ycf ycy yda yde ydy yea yeb yec yed yee yef yey yfa yfc yfd yfe yff yyb yyc yye yyf yyy