On a runway with a circumference of 400 meters, there are two points A and B 100 meters apart. Two people, A and B, run from A and B respectively in opposite directions at the same time. After meeting, B turns around and runs in the same direction as A. When A runs to A, B happens to run to B. When A caught up with B, how many meters did A run in total?
周长为400米的跑道上，有相距100米的A、B两点．甲、乙二人分别从A、B同时反向跑步．相遇后，乙即转身与甲同向跑步，当甲跑到A时，乙恰好跑到B．当甲追上乙时，甲共跑了多少米．
<gadget id="calculator">3 / 4</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 - (1/2)</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(3/4) / (1/2)</gadget>
<output>3/2 = around 1.5</output>

<gadget id="calculator">(3/2) * 400</gadget>
<output>600</output>

<gadget id="calculator">400 + 600</gadget>
<output>1_000</output>

<result>1_000</result>