Triskaidekaphobia fear number 13 ordinary people suffer phobia feel uncomfortable number 13 130 513 etc programmer fear step for example consider number 7 its ok write decimal write base 4 13 dreadful numberthe think bad look Number 100 13 notation contain 13 and number 13 infinite number notation luckily math binary completely safe nasty number but want able estimate level nastiness number your task give integer n find number different integer basis b b2 n write base b contain 13 Assume digits number basis large 10 write letter decimal number 30 base 16 1E 114 simply 114 please note 13 present substre notation subsequence 123 do not contain 13