C C c c c c c c c c C c c c c c c c X X X X X X X X X X X Xxx X X X X X Xx x x x xx x 00 oo oooo o o 0 0 0 0 4 0 0 6 6 6 6 6 6 6 6 77 7 4 4 4 4 ----------- --- _ ----------------- _ __ __ -- - . / / // / / +•• :;