R                           Z                          ZZ                          ZZN N N N N N NN N N N N N NZHMMMMMMMMMMMMMMMMMMMMMMMMMMHH                          HH HMMMMMMMMMMMMMMMMMMMMMMH HMMH NNNNNNNNNNNNNNNNNNNN HMMNNHNHMMMMMMMMMMMMMMMMMMHNHNNMMMMH                  HMMMM    H HMMMMMMMMMMMMMMH H    MMMMMMH NNNNNNNNNNNN HMMMMMMNNNNNNHNHMMMMMMMMMMHNHNNNNNNMMMMMMMMH          HMMMMMMMM        H HMMMMMMH H        MMMMMMMMMMH NNNN HMMMMMMMMMMNNNNNNNNNNHNHMMHNHNNNNNNNNNNMMMMMMMMMMMMHEEHMMMMMMMMMMMM            HNNH            MMMMMMMMMMMMMMMMMMMMMMMMMMMM