my @keys =
    sort { $bdry{ $b->[0] }{ $b->[1] } <=> $bdry{ $a->[0] }{ $a->[1] } }
     map { my $k = $_; map { [$k, $_] } keys %{ $bdry{$k} } }
    keys %bdry;

print "my greatest key-pair is: $bdry{$keys[0][0]}{$keys[0][1]}\n\n";

print "key-pair(@$_) is: $bdry{$_->[0]}{$_->[1]}\n" for @keys;