finding ntpdate in syncing or not ( positive or negative in perl )

#!/usr/bin/perl
@s=readpipe("ntpdate -q 0.centos.pool.ntp.org");
for($i=0;$i<@s;$i++)
{
if ( $s[$i] =~ /sec/i )
{
@e=split(" ",$s[$i]);
$el=@e;
$el1=($el -2);
if ( $e[$el1] > 0 )
{
print "positive"."\n";
}
elsif ( $e[$el1] < 0 )
{
print "Negative $e[$el1].\n";
}
}
}