#! Perl -w
# clhypo.pl -- Hypotenuse command line version
use strict;
my($a, $b, $c) = @ARGV;

if ($c eq "-") {
	$c = sqrt($a**2 + $b**2);
	print "C is $c";
} elsif ($b eq "-") {
	die "A cannot be greater than or equal to C!" if $a >= $c; 
	$b = sqrt($c**2 - $a**2);
	print "B is $b";
} elsif ($a eq "-") {
	die "B cannot be greater than or equal to C!" if $b >= $c; 
        $a = sqrt($c**2 - $b**2);
	print "A is $a";
}