A train, counting from the time when the front of the train arrives at the entrance of the cave, takes 16 seconds to drive all the way into the cave, and the rear of the train leaves the cave after 45 seconds. It is known that the cave is 638 meters long, how many meters is the total length of the train?
一列火车，从车头达到山洞的洞口算起，用16秒全部行驶进山洞，45秒后车尾离开山洞．已知山洞长638米，火车全长多少米？
<gadget id="calculator">45 - 16</gadget>
<output>29</output>

<gadget id="calculator">638 / 29</gadget>
<output>22</output>

<gadget id="calculator">22 * 45</gadget>
<output>990</output>

<gadget id="calculator">990 - 638</gadget>
<output>352</output>

<result>352</result>