my %rmax;
$rmax{$_} = (sort { $r{$_}->{$b} <=> $r{$_}->{$a} } keys %{$r{$_}})[0]
  for keys %r;
print "\$r{$_}{$rmax{$_}} ==> $r{$_}{$rmax{$_}}\n" for keys %rmax;