$ perl foo.pl
$VAR1 = {
          'KEY12' => {
                       'c' => 30,
                       'a' => 10,
                       'b' => 20,
                       'd' => 40
                     },
          'KEY11' => {
                       'c' => 3,
                       'a' => 30,
                       'b' => 40,
                       'd' => 4
                     }
        };