There are 49 trees on one side of the road, and the distance between the two trees is 50 meters. Now install street lamps at intervals of 40 meters on one side of the road. How many street lamps do you need in total?
马路的一侧有49棵树，两棵树之间的距离是50米．现在在路的一侧每隔40米的距离安装路灯，共需要装路灯多少盏？
<gadget id="calculator">49 - 1</gadget>
<output>48</output>

<gadget id="calculator">48 * 50</gadget>
<output>2_400</output>

<gadget id="calculator">2_400 / 40</gadget>
<output>60</output>

<gadget id="calculator">60 + 1</gadget>
<output>61</output>

<result>61</result>