open(NPBXNUM1, ">npbxnum1");
open(MYINPUTFILE, "npbxnum");

while (<MYINPUTFILE>) {
   my($line) = $_;
   chomp($line);
			
   foreach my $inputData ($line) {
			
      my $outputData = $inputData;
      while (length($outputData) < 4) {
         $outputData .= '_';
      }
   print NPBXNUM1 "$outputData\n";
   }
}
close(MYINPUTFILE);
close(NPBXNUM1);