-er a-a a-t aaa aae aak aan aar aat aax aea aee aek aen aer aet aex aka ake akk akn akr an- ana ane ank ann anr ant anx ar- ara are ark arn arr art arx at- ata ate atn atr att atx ax- axa axe axk axn axr axt axx eaa eae eak ean ear eat eax eea eee eek een eer eet eex eka eke ekr ekt en- ena ene enk enn enr ent era ere erk ern err ert eta ete etk etn etr ett etx ex- exa exe exr ext exx k-t ka- kaa kae kak kan kar kat kax ke- kea kee kek ken ker ket kex kke kkk kkn kkr kkt kn- kna kne knk knn knr knt knx kra krk krn krr krt kta kte ktk ktn ktr ktt naa nae nak nan nar nat nax ne- nea nee nek nen ner net nex nka nke nkk nkn nkr nkt nna nne nnk nnn nnt nra nre nrk nrn nrr nrt nrx nta nte ntk ntn ntr ntt ntx nxt ra- raa rae rak ran rar rat rax re- rea ree rek ren rer ret rex rke rkk rkt rna rnn rnr rnt rra rrk rrn rrr rrt rta rte rtk rtn rtr rtt rtx rxr t-x taa tae tak tan tar tat tax te- tea tee tek ten ter tet tex tka tke tkk tkr tkt tna tne tnk tnn tnr tnt tnx tra tre trk trn trr trt trx tta tte ttk ttn ttr ttt ttx txe txk txn txt xaa xak xan xar xat xee xen xer xet xex xke xna xnk xrt xrx xtr xtx xxx