turtle.refuel()
distance = 50
x = 0
y = 0
start = true
space =0;

function mine(distance)
  x = 0
  while x < distance do
    space = turtle.getItemSpace()
    turtle.dig()
    turtle.digUp

    turtle.forward()
    x = x + 1
  end
end
--[[
function isFull()
  if turtle.getItemSpace() = space then
    return true
  else
    return false
  end
--]]
function goBack()
    turtle.turnRight()
    turtle.turnRight()
    for i = 1, x, 1
    do
    turtle.forward()
    end
    turtle.turnRight()
    for i = 1, y, 1
    do
    turtle.forward()
    end
    error()
	end


function mineBack(distance)
  turtle.turnRight()
  turtle.dig()
  turtle.digUp()
  turtle.forward()
  y = y + 1
  turtle.turnRight()

end
if not turtle.getFuelLevel() - ( distance * 2 ) + y > 0 then
  turtle.refuel()
end
while turtle.getFuelLevel() - ( distance * 2 ) + y > 0 do
	if start then
	start = false
	else
	print("beep")
	turtle.turnLeft()
	turtle.dig()
  turtle.digUp()
	turtle.forward()
	turtle.turnLeft()
	y = y + 1
	end
  mine(distance)
  mineBack(distance)
 mine(distance)

  end

  turtle.turnRight()

  for i = 1, y, 1
  do
  turtle.forward()
  end