21 ¹    , "    ,    '          ²         ,  ,  ,  ,    ³                       ⁴              ⁵                        ⁶                                ⁷                        ⁸                ,  ,             ⁹                  ¹⁰                                     ¹¹                       ¹²                           ¹³        ¹⁴                                         ¹⁵                    '" ¹⁶    , ¹⁷ "    , '                                  ¹⁸                             ¹⁹        ²⁰                                           ²¹                                         ²²              ²³                                     '" ²⁴                       