Two ships, A and B, set off from port A and port B at the same time and head towards each other. Ship A travels 18 kilometers per hour, and ship B travels 15 kilometers per hour. After 6 hours, the two ships meet on the way. How many miles is the waterway between the two places?
甲乙两艘轮船分别从A、B两港同时出发相向而行，甲船每小时行驶18千米，乙船每小时行驶15千米，经过6小时两船在途中相遇．两地间的水路长多少千米？
<gadget id="calculator">18 + 15</gadget>
<output>33</output>

<gadget id="calculator">33 * 6</gadget>
<output>198</output>

<result>198</result>