Asian flying man Liu Xiang's strength is the 110-meter hurdles. The 110-meter hurdles track has a total length of 110 meters. There are hurdles every 5 meters. There are no hurdles at the beginning and end. How many hurdles are needed in total?
亚洲飞人刘翔的强项是110米栏，110米栏的赛道全长110米，每隔5米设置一个跨栏，起点和终点不设跨栏，共需要多少个跨栏．
<gadget id="calculator">110 / 5</gadget>
<output>22</output>

<gadget id="calculator">22 - 1</gadget>
<output>21</output>

<result>21</result>