Two ropes are the same length, the first one is cut off by 7 cm, and the second one is cut off by 19 cm. How many centimeters longer is the first one than the second one?
两根绳子一样长，第一根剪去7厘米，第二根剪去19厘米，第一根剩下的比第二根剩下的长多少厘米．
<gadget id="calculator">19 - 7</gadget>
<output>12</output>

<result>12</result>