Two turtles are running a race. Taking south as the positive direction, the length of tortoise A running is +5 meters, and the length of tortoise B running is -4 meters. Then, what is the distance between the two tortoises in meters?
两只乌龟进行跑步比赛．以南为正方向，乌龟甲跑的长度为+5米，乌龟乙跑的长度为-4米，那么，这两只乌龟的距离是多少米．
<gadget id="calculator">5 - (-4)</gadget>
<output>9</output>

<result>9</result>