and B start from two places 20 kilometers apart and walk towards each other. A puppy and A start running towards B at the same time. When it meets B, it immediately turns around and runs towards A. B runs away...until A and B meet each other. It is known that A's speed is 6 km/h, B's speed is 4 km/h, and the puppy's speed is 13 km/h. During this process, how many kilometers did the puppy run in total?
甲，乙两人从相距20千米的两地出发相向而行，一只小狗与甲同时出发向乙奔去，遇到乙后立即掉头向甲跑去，遇到甲后又立即掉头向乙跑去…直到甲乙两人相遇为止．已知甲的速度是6千米/小时，乙的速度是4千米/小时，小狗的速度是13千米/小时，在这一过程中，小狗共跑了多少千米．
<gadget id="calculator">6 + 4</gadget>
<output>10</output>

<gadget id="calculator">20 / 10</gadget>
<output>2</output>

<gadget id="calculator">2 * 13</gadget>
<output>26</output>

<result>26</result>