It's holiday, Xiaogang is going to grandpa's house. Starting from his home, he must first take a car to the front of the mountain. There are 4 buses to the front of the mountain every morning. There are 3 roads to cross the mountain, one is to climb the mountain on foot and cross the top of the mountain; the other is to walk through a cave; These three roads can reach the grandfather's house behind the mountain. Children, how many ways can Xiaogang go from home to grandpa's house?
放假了，小刚要到外公家去．他从家出发必须先坐汽车到达山前这个地方，每天上午有4班汽车可到山前．到了山前需要过一座大山，过山的路有3条，一条是步行爬山越过山顶；一条是通过山洞走；还有一条是坐环山小河上的小艇．这三条路都可以到达山后的外公家．小朋友，小刚从家出发到外公家去有几种走法呢？
<gadget id="calculator">4 * 3</gadget>
<output>12</output>

<result>12</result>