local left = true
local done = false
function mine()
	turtle.forward()
	turtle.digDown()
end

function detect()
	done = not done
	if done then
		return true
	end
	if turtle.detect() then
		left = not left
		turtle.down()
	end
end

while true do
	if turtle.detect() then
		if left then
			left = not left
			turtle.turnLeft()
			mine()
			detect()
			turtle.turnLeft()
			turtle.digDown()
		else
			left = not left
			turtle.turnRight()
			mine()
			detect()
			turtle.turnRight()
			turtle.digDown()
		end
	end
	mine()
end