A team of fighters lined up in a solid square team (the number of rows and rows is equal), and there are 12 more people. If one row is added horizontally and vertically, it will be 19 people short of becoming a larger square. Find the number of soldiers in this team.
一队战士排成一个实心正方形队伍(排与列的人数相等)，还多12人，如果横竖各增加一排，成为大一点的正方形则差19人．求这队战士的人数．
<gadget id="calculator">19 - 1</gadget>
<output>18</output>

<gadget id="calculator">12 + 18</gadget>
<output>30</output>

<gadget id="calculator">30 / 2</gadget>
<output>15</output>

<gadget id="calculator">15 * 15</gadget>
<output>225</output>

<gadget id="calculator">225 + 12</gadget>
<output>237</output>

<result>237</result>