D ff f f f f f f f f f f f ff. F f ff f c f f f f f f f f f f f f f f f f f f f f f ff f f f f f f f c c. Ff c. C ff c c. C c c c c c f ff. C f f f ff. F f f f f ff d d d d d d d d d d d d d d. D d d d d d d d d d d d d f f f c c c c c c c c c c c c. C c c c c c c c c c c. C c c c c c c c c. Ff. C c c c c c c c c. C c c c c c c c c c c c c c. C c c c c c c c c. C d c c c c c c c c c c c c c c c. C c c c c c c c c c. C c c c c c