#!/usr/bin/env perl
use utf8;
###############################################################################
# This program computes the median of a list of float values on STDIN.
# 
# Copyright © 2021 Richard Lesh.  All rights reserved.
###############################################################################

use Error::Simple;
use Nice::Try;
use Utils;
use strict;
use warnings;

MAIN:
{
    my $line;
    my $d;
    my $count = 0;
    my $values = [];

    while ($line = <STDIN>) {
        $line = Utils::trim($line);
        try {
            $d = Utils::stod($line);
            push(@{$values}, $d);
            ++$count;
        } catch (Error::Simple $ex) {
            if (length($line) > 0) {
                print "Can't parse input: ", $line, "\n";
            }
        }
    }

    $values = [sort { $a <=> $b } @$values];
    if ($count > 0) {
        my $median;
        if ($count % 2 == 1) {
            $median = $values->[int(($count - 1) / 2)];
        } else {
            my $middle = int($count / 2);
            $median = ($values->[$middle] + $values->[$middle - 1]) / 2.0;
        }
        print Utils::messageFormat("\{0:g\}", $median), "\n";
    }
}