perl -E'@x=split//,"4335443554366887798866555766";$_=<>;chop;print;while($_-4){split//,"99aabb87780";$x=0;$x+=hex(pop)*!!$&+($1&&$x[$1]+7)+($2>1?$x[$2+18]+$x[$3]:$x[$2.$3])while s/(.??)(.?)(.)$//;say" is $x.";print$_=$x}say" is magic."' __END__ 999999999999999999999999999999999 999999999999999999999999999999999 is 231. 231 is 19. 19 is 8. 8 is 5. 5 is 4. 4 is magic.