fuel = turtle.getFuelLevel()
require(math)
 fuel = 500

x = 10

for u = 0,x do
  i = 0
  while i < x-u do
    turtle.dig()
    turtle.digUp()
    turtle.digDown()
    if turtle.forward() == true then
      x = x - 1
    end
  end

  i = 0
  turtle.turnRight()

  while i < x-u do
    turtle.dig()
    turtle.digUp()
    turtle.digDown()
    if turtle.forward() == true then
      x = x - 1
    end
  end
end