A square nursery is full of saplings. Later, 19 more saplings were replanted, so that a row was added horizontally and vertically. How many saplings were there in the original square nursery?
一块正方形苗圃种满了树苗．后来又补种了19棵，使横、竖各增加了一排，原来正方形苗圃中有多少棵树苗．
<gadget id="calculator">19 - 1</gadget>
<output>18</output>

<gadget id="calculator">18 / 2</gadget>
<output>9</output>

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

<result>81</result>