ooo

length = 5
width = 6
height = 5

-- getting the neccessary amount of fuel
success = turtle.refuel(math.ceil(length * height * width / 160) + math.ceil(width * height / 160))
if not success then
    print("place the fuel to the active slot")
    exit()
end

for h=0,height-1,1 do
    for w=1,width,1 do
        for l=1,length-1,1 do
            turtle.dig()
            turtle.forward()
        end

        if (w % 2 ~= 0) and (w ~= width) then
            turtle.turnLeft()
            turtle.dig()
            turtle.forward()
            turtle.turnLeft()
        elseif (w ~= width) then
            turtle.turnRight()
            turtle.dig()
            turtle.forward()
            turtle.turnRight()
        end
    end
    -- returning to the start point
    turtle.turnLeft()
    for w=1,width-1,1 do
        turtle.forward()
    end
    turtle.turnLeft()
    -- digging down
    turtle.digDown()
    turtle.down()
end