function checkFuel()
	if turtle.getFuelLevel()<1 then
		turtle.up()
		while not turtle.refuel() do 
			sleep(2) 
		end
		turtle.down()
	end
end

while true do
	while turtle.forward() do
		checkFuel()
		while turtle.placeDown() do end
	end
	local _, chest = turtle.inspect()
	if chest and (chest.name:find("chest") or chest.name:find("barrel")) then
		for i = 2, 16 do
			turtle.select(i)
			turtle.drop()
		end
		turtle.select(1)
		local shears = turtle.getItemDetail()
		if not (shears and shears.name == "minecraft:shears") then
			turtle.suck(1)
			shears = turtle.getItemDetail()
			assert(shears and shears.name == "minecraft:shears", "Shears required to run!")
		end
	end
	turtle.turnLeft()
	turtle.turnLeft()
end