local strip = 0
	local tunnel = 0
	local userinput = ""
	local dir = 0
	local x = 0
	local y = 0

	local a = 0
	local b = 0
	local c = false
	local d = 0

	local function eingabe()
		local bool = true



		while bool do
			term.setCursorPos(1,1)
			term.clear()
			print("Wie Lang soll der Tunnel sein?")
			print(" >> ")
			tunnel = tonumber(read())

			if tunnel > 9 then
				print("Wie Lang sollen die Seitengaenge sein?")
				print(" >> ")
				strip = tonumber(read())

				if strip > 2 then
					bool = false
				else
					term.setCursorPos(1,1)
					term.clear()
				end

			else
				term.setCursorPos(1,1)
				term.clear()
			end
		end
	end



	local function notfull()
		for i = 1, 16 do
			if turtle.getItemCount(i) == 0 then
				return true
			end
		end
		return false
	end

	local function betrag(x)
		if (x < 0) then
			return ((-1)*x)
		else
			return x
		end
	end

	local function vor()
		a = betrag(x)
		b = betrag(y)
		c = notfull()
		d = turtle.getFuel()
		if (d) > (a + b + 4)) and c then
			turtle.forward()
			if (dir == 0) then
					x = x + 1
				elseif (dir == 1) then
					y = y + 1
				elseif (dir == 2) then
					x = x - 1
				elseif (dir == 3) then
					y = y - 1
			end
		end
	end

	local function dig()
		a = betrag(x)
		b = betrag(y)
		c = notfull()
		d = turtle.getFuel()
		if (d) > (a + b + 4) and c then
			turtle.dig()
			vor()
			turtle.digUp()
		end
	end

	local function left()
		turtle.turnLeft()
		if dir > 0 then
			dir = dir - 1
		else
			dir = 3
		end
	end

	local function right()
		turtle.turnRight()
		if dir < 3 then
			dir = dir + 1
		else
			dir = 0
		end
	end

	local function home()
		term.clear()
		term.setCursorPos(1,1)
		print("HOME")
	end

	local function stripdig()
		left()
		while (y > (-1)*strip) do
			dig()
		end
		left()
		left()
		while (y ~= 0) do
			vor()
		end
		while (y < strip) do
			dig()
		end
		left()
		left()
		while (y ~= 0) do
			vor()
		end
		right()
	end








	eingabe()

	term.clear()
	term.setCursorPos(1,1)
	print("Progress...")

	a = betrag(x)
	b = betrag(y)
	c = notfull()
	d = turtle.getFuel()

	while (d) > (a + b + 4)) and c do
		if (x%3) == 2 then
			stripdig()
		end

		dig()
		a = betrag(x)
		b = betrag(y)
		c = notfull()
		d = turtle.getFuel()
	end

	home()