hole

local run = true
local level = 0
local tries = 0
function forward(i)
  for x = 1, i do
    while not turtle.forward() do
      tries = tries + 1
      turtle.dig()
      if tries > 10 then
        tries = 0
        return false
      end
    end
    tries = 0
  end
  return true
end
function square()
  forward(4)
  turtle.turnRight()
  forward(4)
  turtle.turnRight()
  forward(4)
  turtle.turnRight()
  for i = 1, 3 do
    forward(4-i)
    turtle.turnRight()
    forward(4-i)
    turtle.turnRight()
  end
  for i = 1, 2 do
    turtle.turnRight()
    forward(2)
  end
  turtle.turnRight()
end
while turtle.getFuelLevel() > level and run do
  square()
  turtle.digDown()
  if not turtle.down() then
    run = false
  end
  level = level + 1
end
while level > 0 do
  turtle.digUp()
  if turtle.up() then
    level = level - 1
  end
end