-er a-a a-b a-c a-t aaa aab aac aad aae aar aat aax ab- aba abb abc abd abe abr abt abx ac- aca acb acc acd ace acr act acx ad- ada adb adc add ade adr adt adx aea aeb aec aed aee aer aet aex ar- ara arb arc ard are arr art arx at- ata atb atc atd ate atr att atx ax- axa axe axr axt axx baa bab bac bad bae bar bat bax bba bbb bbc bbd bbe bbr bbt bbx bca bcb bcc bcd bce bcr bct bcx bda bdb bdc bdd bde bdr bdt bdx be- bea beb bec bed bee ber bet bex bra brb brd bre brr brt brx bta btb btc btd bte btr btt btx bxb bxd bxx c-- caa cab cac cad cae car cat cax cba cbb cbc cbd cbe cbr cbt cbx cca ccb ccc ccd cce ccr cct ccx cda cdb cdc cdd cde cdr cdt cdx ce- cea ceb cec ced cee cer cet cex cra crb crc crd cre crr crt crx cta ctb ctc ctd cte ctr ctt ctx cxc cxr cxt cxx daa dab dac dad dae dar dat dax dba dbb dbc dbd dbe dbr dbt dbx dca dcb dcc dcd dce dcr dct dcx dda ddb ddc ddd dde ddr ddt ddx de- dea deb dec ded dee der det dex dra drb drc drd dre drr drt drx dta dtb dtc dtd dte dtr dtt dtx dxc dxd dxr dxt dxx eaa eab eac ead eae ear eat eax eba ebb ebc ebd ebe ebr ebt ebx ec- eca ecb ecc ecd ece ecr ect ecx ed- eda edb edc edd ede edr edt edx eea eeb eec eed eee eer eet eex era erb erc erd ere err ert eta etb etc etd ete etr ett etx ex- exa exc exd exe exr ext exx ra- raa rab rac rad rae rar rat rax rba rbb rbc rbd rbe rbr rbt rbx rca rcb rcc rcd rce rcr rct rcx rda rdb rdc rdd rde rdr rdt rdx re- rea reb rec red ree rer ret rex rra rrb rrc rrd rrr rrt rta rtb rtc rtd rte rtr rtt rtx rxr t-x taa tab tac tad tae tar tat tax tba tbb tbc tbd tbe tbr tbt tca tcb tcc tcd tce tcr tct tcx tda tdb tdc tdd tde tdr tdt tdx te- tea teb tec ted tee ter tet tex tra trb trc trd tre trr trt trx tta ttb ttc ttd tte ttr ttt ttx txe txt xaa xac xad xar xat xbc xbe xbr xbx xcb xcd xcr xcx xda xdb xdc xde xdr xdt xed xee xer xet xex xrc xrd xrt xrx xtc xtr xtx xxx