lbeck bleck lebck elbck belck eblck lbcek blcek lcbek clbek bclek cblek lecbk elcbk lcebk clebk eclbk celbk beclk ebclk bcelk cbelk ecblk ceblk lbekc blekc lebkc elbkc belkc eblkc lbkec blkec lkbec klbec bklec kblec lekbc elkbc lkebc klebc eklbc kelbc beklc ebklc bkelc kbelc ekblc keblc lbcke blcke lcbke clbke bclke cblke lbkce blkce lkbce klbce bklce kblce lckbe clkbe lkcbe klcbe cklbe kclbe bckle cbkle bkcle kbcle ckble kcble leckb elckb lcekb clekb eclkb celkb lekcb elkcb lkecb klecb eklcb kelcb lckeb clkeb lkceb klceb ckleb kcleb ecklb ceklb ekclb keclb ckelb kcelb beckl ebckl bcekl cbekl ecbkl cebkl bekcl ebkcl bkecl kbecl ekbcl kebcl bckel cbkel bkcel kbcel ckbel kcbel eckbl cekbl ekcbl kecbl ckebl kcebl
Note: these 'words' (valid or invalid) are all the permutations of the word lbeck. These words are obtained by scrambling the letters in lbeck.