1,604 students from Hope Primary School lined up to watch a movie in 4 columns. The distance between the two students was 5 decimeters. It took them 20 minutes to cross a bridge. If the speed of the team is 25 meters per minute, how long is the bridge?
希望小学1604名学生排成4路纵队去看电影，前后两个学生中间相距5分米，他们通过一座大桥用去20分钟，如果队伍前进的速度是每分钟25米，那么桥长多少米？
<gadget id="calculator">25 * 20</gadget>
<output>500</output>

<gadget id="calculator">1_604 / 4</gadget>
<output>401</output>

<gadget id="calculator">401 - 1</gadget>
<output>400</output>

<gadget id="calculator">400 * 0.5</gadget>
<output>200</output>

<gadget id="calculator">500 - 200</gadget>
<output>300</output>

<result>300</result>