#!/usr/bin/perl -l
use warnings;
use strict;

my @x;
print "Please enter one number per line (empty line ends input):";
while (<STDIN>){ last if /^$/; push @x, $_; }
print "The biggest number is ", (sort {$b<=>$a} @x)[0],
    "@x" =~ /^([-0-9]+)\s+(?:\1\s+)*$/ && "All numbers are the same";