There are a row of trees planted equidistantly on the side of the road. Xiaolin started walking from the first tree to the fourth tree in 12 seconds, so how many trees should he reach after walking for 1 minute?
路边等距离地种着一排树，小林从第1棵树开始散步，到第4棵树用了12秒，那么散步1分钟，应到第多少棵树旁．
<gadget id="calculator">4 - 1</gadget>
<output>3</output>

<gadget id="calculator">12 / 3</gadget>
<output>4</output>

<gadget id="calculator">60 / 4</gadget>
<output>15</output>

<gadget id="calculator">1 * 15</gadget>
<output>15</output>

<gadget id="calculator">15 + 1</gadget>
<output>16</output>

<result>16</result>