fcfda cffda ffcda ffcda cffda fcfda fcdfa cfdfa fdcfa dfcfa cdffa dcffa ffdca ffdca fdfca dffca fdfca dffca cfdfa fcdfa cdffa dcffa fdcfa dfcfa fcfad cffad ffcad ffcad cffad fcfad fcafd cfafd facfd afcfd caffd acffd ffacd ffacd fafcd affcd fafcd affcd cfafd fcafd caffd acffd facfd afcfd fcdaf cfdaf fdcaf dfcaf cdfaf dcfaf fcadf cfadf facdf afcdf cafdf acfdf fdacf dfacf fadcf afdcf dafcf adfcf cdaff dcaff cadff acdff dacff adcff ffdac ffdac fdfac dffac fdfac dffac ffadc ffadc fafdc affdc fafdc affdc fdafc dfafc fadfc afdfc daffc adffc fdafc dfafc fadfc afdfc daffc adffc cfdaf fcdaf cdfaf dcfaf fdcaf dfcaf cfadf fcadf cafdf acfdf facdf afcdf cdaff dcaff cadff acdff dacff adcff fdacf dfacf fadcf afdcf dafcf adfcf
Note: these 'words' (valid or invalid) are all the permutations of the word fcfda. These words are obtained by scrambling the letters in fcfda.