@clusters =(0..37);
opendir (DIR, ".") or die "$!";
@files =  grep {/cluster/}  readdir DIR;print @files;
for $clusters ( @clusters)
  {
    for $files (@files)
      {
	if ($files =~ /$clusters\_g/)
	  {
	  $file = $files;
	  print "$clusters $file\n";
          }
      }
  }