Xiao Ming and Xiao Hua walk toward each other from two places 300 meters apart at the same time. Xiao Ming travels 80 meters in each branch, and Xiao Hua travels 70 meters in each branch. Then he turned his head and ran towards Xiao Ming, and then ran towards Xiao Hua when he met Xiao Ming, and kept going back and forth in this way until Xiao Ming and Xiao Hua met. How many meters did the puppy run?
小明和小华同时从相距300米的两地相向而行，小明每分行80米，小华每分行70米，如果一只狗与小明同时同向而行，每分行400米，遇到小华后立即回头向小明跑去，遇到小明后再向小华跑去，这样不断来回，直到小明和小华相遇为止，小狗跑了多少米？
<gadget id="calculator">80 + 70</gadget>
<output>150</output>

<gadget id="calculator">300 / 150</gadget>
<output>2</output>

<gadget id="calculator">2 * 400</gadget>
<output>800</output>

<result>800</result>