There are 51 flags planted next to a straight runway with an interval of 2 meters. Later, only 26 small flags were planted. How many meters are the average interval? (both ends plugged in)
在一条笔直的跑道旁插着51面旗，间隔是2米，后来改为只插26面小旗，平均间隔多少米？(两端都插)
<gadget id="calculator">51 - 1</gadget>
<output>50</output>

<gadget id="calculator">50 * 2</gadget>
<output>100</output>

<gadget id="calculator">26 - 1</gadget>
<output>25</output>

<gadget id="calculator">100 / 25</gadget>
<output>4</output>

<result>4</result>