In the school sports meeting, primary school students form a large phalanx. There are 25 people on each side of the outermost phalanx, a total of 8 floors; the middle part is the emblem of the sports meeting composed of 15 students. How many students are there in this phalanx?
学校运动会上，小学生组成一个大型方阵队，方阵队最外层每边25人，共8层；中间部分是15名同学组成的运动会会徽，这个方阵队共有多少名学生？
<gadget id="calculator">25 ** 2</gadget>
<output>625</output>

<gadget id="calculator">2 * 8</gadget>
<output>16</output>

<gadget id="calculator">25 - 16</gadget>
<output>9</output>

<gadget id="calculator">9 ** 2</gadget>
<output>81</output>

<gadget id="calculator">625 - 81</gadget>
<output>544</output>

<gadget id="calculator">544 + 15</gadget>
<output>559</output>

<result>559</result>