A train travels from City A to City B. If it travels at a speed of 60 kilometers per hour, the train will be delayed by 2 hours; if the speed is changed to 70 kilometers per hour, the train will arrive at City B one hour earlier. , How long is the railway between A and B?
一列火车从甲城开往乙城，如果按每小时60千米的速度行驶下去，火车就要晚点2小时；如果速度改为每小时70千米行驶下去，火车就可提前1小时到达乙城，甲乙两城间的铁路有多长？
<gadget id="calculator">60 * 2</gadget>
<output>120</output>

<gadget id="calculator">70 * 1</gadget>
<output>70</output>

<gadget id="calculator">120 + 70</gadget>
<output>190</output>

<gadget id="calculator">70 - 60</gadget>
<output>10</output>

<gadget id="calculator">190 / 10</gadget>
<output>19</output>

<gadget id="calculator">19 + 2</gadget>
<output>21</output>

<gadget id="calculator">60 * 21</gadget>
<output>1_260</output>

<result>1_260</result>