@data = <IN>;
my @sorted_data = sort @data;
foreach $line (@sorted_data) {
  chomp $line;
  $line =~ /(.*?)\,(.*?)\,(.*)/;
  $first = $1;
  $second = $2;
  $last = $3;
  if ($last eq $second) {
    if($second eq $first) {
      $print "$second really = $first\n";
       } else {
         print "$last only = $first\n";
         }
       }
  }