jfloor

y=0

function fleeUp()
  for i=1,y do
    turtle.digUp()
    turtle.up()
  end
end

function moveDown()
  if turtle.detectDown() then
    turtle.digDown()
  end
  if turtle.down() then
    y=y+1
  end
end

function floorOne()
  local retval = false
  local slot = 0
  slot = turtle.getSelectedSlot()
  if turtle.getItemCount(slot) == 0 then
    if slot < 16 then
      turtle.select(slot+1)
      turtle.placeDown()
      retval = true
    else
      retval = false
    end
  else
    turtle.placeDown()
    retval = true
  end
  return retval
end

function moveForward()
  if turtle.detect() then
    turtle.dig()
  end
  return turtle.forward()
end

turtle.select(1)
while y < 63 do
  for i=1,4 do
    moveDown()
  end
  turnRight = true
  for i=1,9 do
    for j=1,8 do
      if not floorOne() then fleeUp(); shell.exit() end
      moveForward()
    end
    if not floorOne() then fleeUp(); shell.exit() end
    if i==9 then
      turtle.turnRight()
      turtle.turnRight()
    else
      if turnRight then
        turtle.turnRight()
        moveForward()
        turtle.turnRight()
      else
        turtle.turnLeft()
        moveForward()
        turtle.turnLeft()
      end
    end
    turnRight = not turnRight
  end
end
turtle.select(1)