all know girl Arpas land ok you ve get idea DAnyone know Arpa is not normal man sorry I can not explain Mehrdad interested reason ask Sipa good biology scientist Arpas land help Sipa dna editor Sipa Arpa DNA editor dna editor show Arpas dna string S consist n lowercase english letter also Sipa dna T consist lowercase English letter belong normal manNow n1 option change Arpas DNA number 0 n ith T ith i1th character S 0 in if i0 T S SMehrdad wants choose interesting option Arpas DNA n1 option dna a interesting b a lexicographically small B Mehrdad ask Sipa q question give integer lrkxy interesting option consider option lir if interesting option Mehrdad want know small number iSince Sipa biology scientist programmer help