infra nifra ifnra finra nfira fnira inrfa nirfa irnfa rinfa nrifa rnifa ifrna firna irfna rifna frina rfina nfria fnria nrfia rnfia frnia rfnia infar nifar ifnar finar nfiar fniar inafr niafr ianfr ainfr naifr anifr ifanr fianr iafnr aifnr fainr afinr nfair fnair nafir anfir fanir afnir inraf niraf irnaf rinaf nriaf rniaf inarf niarf ianrf ainrf nairf anirf iranf rianf iarnf airnf rainf arinf nraif rnaif narif anrif ranif arnif ifran firan irfan rifan frian rfian ifarn fiarn iafrn aifrn fairn afirn irafn riafn iarfn airfn raifn arifn frain rfain farin afrin rafin arfin nfrai fnrai nrfai rnfai frnai rfnai nfari fnari nafri anfri fanri afnri nrafi rnafi narfi anrfi ranfi arnfi frani rfani farni afrni rafni arfni
Note: these 'words' (valid or invalid) are all the permutations of the word infra. These words are obtained by scrambling the letters in infra.