turtle.select(15)
turtle.refuel()
function checkAndDrop()
  occ = 0
  for i = 1,12,1 do
    if turtle.getItemCount(i) > 0 then
      occ = occ + 1
    end
  end
  if occ > 8 then
    turtle.turnRight()
    turtle.dig()
    turtle.select(13)
    turtle.place()
    for i = 1,12,1 do
      turtle.select(i)
      turtle.drop()
    end
    turtle.turnLeft()
  end
end
function digThree(val)
    turtle.dig()
    turtle.forward()
    turtle.digDown()
    turtle.digUp()
    turtle.down()
    if not turtle.detectDown() then
      turtle.select(14)
      turtle.placeDown()
    end
    turtle.up()
    turtle.back()
end
function left()
    turtle.turnLeft()
    turtle.forward()
    turtle.turnRight()
end
function right()
    turtle.turnRight()
    turtle.forward()
    turtle.turnLeft()
end
level = 0
while (turtle.getFuelLevel() > 10) do
    level = level + 1
    digThree(12)
    left()
    digThree(11)
    left()
    digThree(10)
    right()
    right()
    if level % 5 == 0 then
      turtle.turnLeft()
      turtle.select(16)
      turtle.place()
      turtle.turnRight()
    end
    turtle.forward()
    turtle.down()
    checkAndDrop()
    if level == 100 then
      break
    end
end
turtle.turnLeft()
turtle.turnLeft()

while (level > 0) do
  turtle.up()
  turtle.forward()
  level = level - 1
end