-er a-a a-t aaa aad aae aar aat aax ad- ada add ade adr adt adx aea aed aee aer aet aex ar- ara ard are arr art arx at- ata atd ate atr att atx ax- axa axe axr axt axx daa dad dae dar dat dax dda ddd dde ddr ddt ddx de- dea ded dee der det dex dra drd dre drr drt drx dta dtd dte dtr dtt dtx dxd dxr dxt dxx eaa ead eae ear eat eax ed- eda edd ede edr edt edx eea eed eee eer eet eex era erd ere err ert eta etd ete etr ett etx ex- exa exd exe exr ext exx ra- raa rad rae rar rat rax rda rdd rde rdr rdt rdx re- rea red ree rer ret rex rra rrd rrr rrt rta rtd rte rtr rtt rtx rxr t-x taa tad tae tar tat tax tda tdd tde tdr tdt tdx te- tea ted tee ter tet tex tra trd tre trr trt trx tta ttd tte ttr ttt ttx txe txt xaa xad xar xat xda xde xdr xdt xed xee xer xet xex xrd xrt xrx xtr xtx xxx