In the group gymnastics performance for the Olympic Games, a certain school formed a phalanx with equal numbers of horizontal and vertical rows and a total number of 225 students. How many students are there in the outermost layer of the phalanx?
在迎奥运团体操表演中，某校组成了横排和竖排人数相等且总人数是225人的方阵，这个方阵最外层的学生共有多少人．
<gadget id="calculator">15 - 1</gadget>
<output>14</output>

<gadget id="calculator">14 * 4</gadget>
<output>56</output>

<result>56</result>