There are 51 street lamps installed on both sides of Renmin Road from the beginning to the end, and every two adjacent lamps are separated by 10 meters. How many meters is the total length of this road?
人民路两旁从头到尾各安装了51盏路灯，每相邻两盏间隔10米，这条马路全长多少米？
<gadget id="calculator">51 - 1</gadget>
<output>50</output>

<gadget id="calculator">50 * 10</gadget>
<output>500</output>

<result>500</result>