Garden workers plant trees on both sides of a sidewalk (including the endpoints). The distance between two adjacent trees on each side of the road is 5 meters. If there are 100 trees planted in total, how many meters is the sidewalk?
园林工人在一条人行道的两旁植树(包括端点)，路每边相邻的两棵树相距都是5米，一共植树100棵，则这条人行道有多少米．
<gadget id="calculator">100 / 2</gadget>
<output>50</output>

<gadget id="calculator">50 - 1</gadget>
<output>49</output>

<gadget id="calculator">5 * 49</gadget>
<output>245</output>

<result>245</result>