#!/usr/bin/perl
@a=pop=~/(.)/g;while(+@a>1){my(@b,$c);print@a,"\n";for(@a){if(''ne$c){$d=$_+$c;my$e;push@b,($d>9)?(do{map{$e+=$_}$d=~/(.)/g;$e}):$d;}$c=$_;}@a=@b;}print@a,"\n";