Perl: Finding higest UID from passwd file

#! /usr/bin/perl -w
use strict;

#
# Program to find the maximum
# User ID from /etc/passwd.
#

use constant CONF_FILE  => "/etc/passwd";  # PATH of the file
use constant SEPERATOR  => ":";              # Record seperator
use constant COLTOSPLIT => 4;               # Number of columns to split.
use constant COL_USRID  => 2;               # User id column number.
my $userID = 0;                        # Temp variable for finding  max UID.

#
# Open /etc/passwd file.
# If any error occurs while
# reading file terminate program
# print the error message occured.
#

open (FILE, CONF_FILE) or die ($!);
my @data = ;

#
# Read one line, split the line using SPERATOR.
# Check value at COL_USRID column.
# Store the maximum UID in userID.
#
foreach my $line (@data) {
  chomp($line);
  my @user =  split(SEPERATOR, $line, COLTOSPLIT);
  if ($userID < $user[COL_USRID]) {
            $userID = $user[COL_USRID];
    }
 }  
# 
# Close the file handler. 
# close(FILE);  
print "Higest user ID : " , $userID; 
print "\n"; exit 0;