Students go out for a spring outing. After the bus travels at a speed of 30 kilometers per hour for 2 hours, it is still 18 kilometers away from the midpoint of the whole journey. How many kilometers is the total length of the spring outing route?
学生外出春游，客车以每小时30千米的速度行了2小时后，距离全程的中点还有18千米，春游的路线全长有多少千米？
<gadget id="calculator">30 * 2</gadget>
<output>60</output>

<gadget id="calculator">60 + 18</gadget>
<output>78</output>

<gadget id="calculator">78 * 2</gadget>
<output>156</output>

<result>156</result>