On both sides of the corridor of the school, pots of chrysanthemums were placed every 4 meters, and a total of 18 pots were placed from the beginning to the end. How many meters is this corridor?
在学校的走廊两侧，每隔4米放一盆菊花，从起点到终点一共放了18盆．这条走廊长多少米？
<gadget id="calculator">18 / 2</gadget>
<output>9</output>

<gadget id="calculator">9 - 1</gadget>
<output>8</output>

<gadget id="calculator">8 * 4</gadget>
<output>32</output>

<result>32</result>