thrcu htrcu trhcu rthcu hrtcu rhtcu thcru htcru tchru cthru hctru chtru trchu rtchu tcrhu ctrhu rcthu crthu hrctu rhctu hcrtu chrtu rchtu crhtu thruc htruc trhuc rthuc hrtuc rhtuc thurc hturc tuhrc uthrc hutrc uhtrc truhc rtuhc turhc utrhc ruthc urthc hrutc rhutc hurtc uhrtc ruhtc urhtc thcur htcur tchur cthur hctur chtur thucr htucr tuhcr uthcr hutcr uhtcr tcuhr ctuhr tuchr utchr cuthr ucthr hcutr chutr huctr uhctr cuhtr uchtr trcuh rtcuh tcruh ctruh rctuh crtuh truch rtuch turch utrch rutch urtch tcurh cturh tucrh utcrh cutrh uctrh rcuth cruth ructh urcth curth ucrth hrcut rhcut hcrut chrut rchut crhut hruct rhuct hurct uhrct ruhct urhct hcurt churt hucrt uhcrt cuhrt uchrt rcuht cruht rucht urcht curht ucrht
Note: these 'words' (valid or invalid) are all the permutations of the word thrcu. These words are obtained by scrambling the letters in thrcu.