if (my @match = split /\s+/) {
    if ($match[-2] =~ /^\d{1,3}$/ and $match[-1] !~ /\D/) {
        $match[-2] = $count++;
    }
    $_ = "@match\n";
}

##</code><code>##

    /([^ ]+)\s+([^ ]+)\s+([^ ]+)...\s+(\d{1,3})\s+(\d+)$/

##</code><code>##

    /(\S+)\s+(\S+)\s+(\S+)\s+...\s+(\d{1,3})\s+(\d+)$/

##</code><code>##

    my $pat = join ( '\\s+', (
       ('(\\S+)' x 15),
       '(\\d{1,3})',
       '(\\d+)',
    ));
    $pat = qr/\A$pat\z/;