There are 26 red flags inserted in a row. The distance between each two sides was originally 4 meters, but now it is changed to 5 meters. If one side of the starting point does not move, how much of it can remain unchanged.
插一排红旗共26面，原来每两面之间的距离是4米，现在改为5米．如果起点一面不移动，还可以有多少不移动．
<gadget id="calculator">26 - 1</gadget>
<output>25</output>

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

<gadget id="calculator">100 / 20</gadget>
<output>5</output>

<result>5</result>