#!/usr/bin/perl
#
# Author: Adam Zemla
# Email: adamz@llnl.gov
# Date: 04/01/2001
#

$pdb=$ARGV[0];
$nb=$ARGV[1];

  $ok=1;
  open(IN,"$pdb") || {$ok=0};
  if($ok==0) {
    print "ERROR: can't open file $pdb \n";
    exit;
  }
  else {
    $ok=0;
    while (<IN>) {
      chomp($line=$_);
      $ok=$ok+1;
      if($ok==$nb) {
        $ok=0;
        print "$line \n";
      }
    }
    close(IN);
  }

exit;