a-a a-b aaa aab aae aaf aak aaw ab- aba abb abe abf abk abw aea aeb aee aef aek aew af- afa afb afe aff afk afw aka akb ake akk akw aw- awa awb awe awf awk aww baa bab bae baf bak baw bba bbb bbe bbf bbk bbw be- bea beb bee bef bek bew bfa bfb bfe bff bka bkb bke bkf bkk bkw bwa bwb bwf bwk eaa eab eae eaf eak eaw eba ebb ebe ebf ebk ebw eea eeb eee eef eek eew ef- efa efb efe eff efw eka ekb eke ekf ewa ewb ewe ewf ewk eww faa fab fae faf fak faw fba fbb fbe fbf fbk fbw fea feb fee fef fek few ffa ffe fff ffk ffw fka fkb fkf fkk fwa fwb fwe fwf ka- kaa kab kae kaf kak kaw kba kbb kbe kbf kbk kbw ke- kea keb kee kef kek kew kfa kff kfw kkb kke kkk kw- kwa kwf kwk kww waa wab wae waf wak waw wba wbb wbe wbf wbw wea web wee wef wek wew wfa wfb wfe wff wfk wfw wka wkb wke wkf wkw wwa wwe wwf www