burq ubrq bruq rbuq urbq rubq buqr ubqr bqur qbur uqbr qubr brqu rbqu bqru qbru rqbu qrbu urqb ruqb uqrb qurb rqub qrub
Note: these 'words' (valid or invalid) are all the permutations of the word burq. These words are obtained by scrambling the letters in burq.