-er bbb bbe bbi bbm bbr bbt bbx be- beb bee bei bem ber bet bex bi- bib bie bii bim bir bit bix bmb bme bmi bmm bmr bmt bmx brb bre bri brm brr brt brx btb bte bti btm btr btt btx bxb bxi bxm bxx ebb ebe ebi ebm ebr ebt ebx eeb eee eem eer eet eex eib eie eii eim eir eit eix em- emb eme emi emm emr emt emx erb ere eri erm err ert etb ete eti etm etr ett etx ex- exe exi exr ext exx ibb ibe ibi ibm ibr ibt ibx ie- iee iei iem ier iet iex iib iie iii iim iir iit iix im- imb ime imi imm imt imx ir- irb ire iri irm irr irt irx itb ite iti itm itt itx ixe ixi m-r mbb mbe mbi mbm mbr mbt mbx meb mee mei mem mer met mex mi- mib mie mii mim mir mit mix mmb mme mmi mmm mmr mmt mmx mrb mre mri mrm mrr mrt mrx mtb mte mti mtm mtr mtt mtx mxi mxr rbb rbe rbi rbm rbr rbt rbx re- reb ree rei rem rer ret rex rib rie rii rim rir rit rix rmb rme rmi rmm rmr rmt rmx rrb rri rrm rrr rrt rtb rte rti rtm rtr rtt rtx rxr t-x tbb tbe tbi tbm tbr tbt te- teb tee tei tem ter tet tex tib tie tii tim tir tit tix tmb tme tmi tmm tmr tmt tmx trb tre tri trm trr trt trx ttb tte tti ttm ttr ttt ttx txe txi txt xbe xbr xbx xee xem xer xet xex xie xii xit xix xmi xmm xmr xmt xmx xrt xrx xti xtm xtr xtx xxi xxx