Hana is driving on the highway. She is looking at her mileage and happens to see a symmetrical number 13931. Hana continued to drive her car. Two hours later, she looked at the odometer again, and she was surprised to find that it was a symmetrical number again. Assuming she doesn't go faster than 70km/h, what is Hana's speed?
哈娜正开车行使在高速公路上，她注视着她行使的公里数，碰巧看到目前所显示的是一个左右对称的数13931．哈娜继续开着她的车，两个小时之后，她再次注视里程表，她吃惊的发现又是一个左右对称的数．假设她的时速不超过70公里每小时，那么哈娜的时速是多少？
<gadget id="calculator">14_041 - 13_931</gadget>
<output>110</output>

<gadget id="calculator">110 / 2</gadget>
<output>55</output>

<result>55</result>