Ry  |   |   |   
X---+---+---@   
Ry  |   |   |   
X---+---@   |   
Ry  |   |   |   
X---+---+---@   
Ry  |   |   |   
X---@   |   |   
Ry  |   |   |   
X---+---+---@   
Ry  |   |   |   
X---+---@   |   
Ry  |   |   |   
X---+---+---@   
Ry  |   |   |   
X---@   |   |   
