625 students participate in the 100-meter race. There are 5 tracks. In each race, 4 players can be eliminated, leaving only the first place to continue to participate in the race. How many races are needed to determine the champion?
625名学生参加100米比赛，跑道有5条，每赛一次可淘汰4名选手，只留下第一名继续参加比赛，需要赛多少次才能决出冠军？
<gadget id="calculator">625 - 1</gadget>
<output>624</output>

<gadget id="calculator">624 / 4</gadget>
<output>156</output>

<result>156</result>