bbb bbe bbl bbn bbt bbx be- beb bee bel ben bet bex blb ble bll bln blt blx bnb bne bnl bnn bnt bnx btb bte btl btn btt btx bxb bxl bxn bxx ebb ebe ebl ebn ebt ebx eeb eee eel een eet eex elb ele ell eln elt elx en- enb ene enl enn ent etb ete etl etn ett etx ex- exe exl ext exx lbb lbe lbl lbt lbx leb lee lel len let lex llb lle lll lln llt lnb lne lnl lnn lnt ltb lte ltl ltt ltx lxx nbb nbe nbl nbn nbt nbx ne- neb nee nel nen net nex nlb nle nll nln nlt nlx nnb nne nnl nnn nnt ntb nte ntn ntt ntx nxl nxt t-x tbb tbe tbl tbn tbt te- teb tee tel ten tet tex tle tll tln tlt tlx tnb tne tnl tnn tnt tnx ttb tte ttl ttn ttt ttx txe txl txn txt xbe xbl xbx xee xel xen xet xex xlb xlt xtx xxl xxx