There are 2 routes from Nanjing to Shanghai, and 4 routes from Shanghai to Nantong. How many different routes are there if you go from Nanjing to Nantong via Shanghai?
从南京到上海有2条行走路线，从上海到南通有4条行走路线，如果从南京经上海到南通，有几种不同的行走路线？
<gadget id="calculator">2 * 4</gadget>
<output>8</output>

<result>8</result>