#!/usr/bin/perl

use strict;
open(FH,"$ARGV[0]") or die;
my @temp=<FH>;
close FH;

my $quadratic = quadratic (\@temp);
print "$quadratic\n";

sub quadratic {     
    my ($a, $b, $c) = @_;
    return (-$b + sqrt($b*$b - 4*$a * $c)) / 2*$a;
}