and B are walking toward each other from AB. They meet at C for the first time and continue on. When A arrives at B, he returns immediately, and B also returns immediately after arriving at A. For the first encounter, it is known that the distance between AD accounts for (1/3) of the distance between AB, the distance between CD is 800 meters, and the distance between AB?
甲乙两人从AB两地相向而行，第一次在C地相遇后继续前行，当甲到达B地后立即返回，乙到达A地后也同样立即返回在，两人在D地第二次相遇，已知AD间距占AB间距离的(1/3)，CD间的距离为800米，AB间距离？
<gadget id="calculator">1_600 + 800</gadget>
<output>2_400</output>

<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">2_400 / (2/3)</gadget>
<output>3_600</output>

<result>3_600</result>