-er a-a a-t aaa aae aag aar aat aax aea aee aeg aer aet aex ag- aga age agg agr agt agx ar- ara are arg arr art arx at- ata ate atg atr att atx ax- axa axe axr axt axx eaa eae eag ear eat eax eea eee eeg eer eet eex ega ege egg egr egt egx era ere erg err ert eta ete etg etr ett etx ex- exa exe exr ext exx gaa gae gag gar gat ge- gea gee geg ger get gex gga ggg ggr ggt gra gre grg grr grt grx gta gte gtg gtr gtt gtx gxa gxt ra- raa rae rag rar rat rax re- rea ree reg rer ret rex rga rge rgg rgr rgt rgx rra rrg rrr rrt rta rte rtg rtr rtt rtx rxr t-x taa tae tag tar tat tax te- tea tee teg ter tet tex tga tge tgg tgr tgt tra tre trg trr trt trx tta tte ttg ttr ttt ttx txe txt xaa xag xar xat xee xeg xer xet xex xge xrt xrx xtr xtx xxx