Secret Number

Score: 64.00 (fail)

#!/usr/bin/perl -l
$_=pop;print,s@.(?=(.))@($&+$+)%9or$&?9:0@ge,chop,while+y///c

Score: 65.00 (pass)

#!/usr/bin/perl -l
$_=pop;print,s@.(?=(.))@($&+$1)=~/./,$'+$&@ge,chop,while+y///c