KYU

W = 12
r = 6
x = 0
y = 0
z = 0
S = 5

function item()
    local X
      X = 1
      while true do
       turtle.select( X )
      if turtle.getItemCount() >= 1 then break
      end
    X = X + 1
      end
end

for n = 1,3 do
 turtle.up()
end

 for z = 1,W do
  for y = 1,W do
   for x = 1,W do
     I = x - r
     J = y - r
     N = z - r
     A = I * I + J * J + N * N

     if A < r * r and S * S < A then turtle.placeDown()
     end

      turtle.forward()

     if x == W then
       for n = 1,12 do
        turtle.back()
     end
      turtle.turnRight()
      turtle.forward()
      turtle.turnLeft()
     end

     if x == W and y == W then
      turtle.up()
      turtle.turnLeft()
     for n = 1,12 do
      turtle.forward()
     end
      turtle.turnRight()
    end
      item()
   end
  end
 end