Cars A and B are traveling opposite each other from AB. Car B travels 56 kilometers per hour and arrives at the midpoint of AB one hour earlier than Car A. When A reaches the midpoint, Car B travels between AB and AB. At point C, the ratio of the distance between car B to point A and the total length is 7:18, how many kilometers is the total length of the two points AB?
甲乙两车分别从AB两地相对而行，乙车每小时行56千米，比甲车早1小时到AB两地的中点，当甲到达中点时，乙车行驶到AB两地间的C地，这时乙车到A地的路程与全长的比是7：18，AB两地全长多少千米？
<gadget id="calculator">7 / 18</gadget>
<output>7/18 = around 0.388889</output>

<gadget id="calculator">1 - (7/18)</gadget>
<output>11/18 = around 0.611111</output>

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

<gadget id="calculator">(11/18) - (1/2)</gadget>
<output>1/9 = around 0.111111</output>

<gadget id="calculator">1 / (1/9)</gadget>
<output>9</output>

<gadget id="calculator">56 * 9</gadget>
<output>504</output>

<result>504</result>