use strict;
use warnings;
use utf8;
use List::Util qw(max);
use List::Util qw(min);

my $input = <STDIN>;
chomp($input);
my @arr = split(/ /, $input);
my $a = $arr[0];
my $b = $arr[1];
my $bigger = max ($a, $b);
my $smaller = min ($a, $b);
my $ans = sqrt($bigger**2 - $smaller**2);
print "$ans\n";