while true do
  sleep(3)

while turtle.detect() do
   turtle.dig()
   turtle.up()
end

while turtle.detectUp() do
   turtle.digUp()
   turtle.up()
   turtle.dig()
end

while not turtle.detectDown() do
   turtle.down()
end

   turtle.turnRight()
   turtle.turnRight()
   turtle.drop()
   turtle.turnLeft()
   turtle.turnLeft()
end