Kindergarten children arrange the chess pieces into a square matrix under the guidance of the teacher. If the horizontal and vertical rows are removed from this square matrix, the square matrix will have 13 fewer chess pieces. So how many chess pieces are there in this square?
幼儿园小朋友在老师的指导下，把棋子排成1个正方形方阵，如果在这个方阵上去掉横竖各一排，则这个方阵少13枚棋子．那么这个方阵共有多少枚棋子？
<gadget id="calculator">13 + 1</gadget>
<output>14</output>

<gadget id="calculator">14 / 2</gadget>
<output>7</output>

<gadget id="calculator">7 * 7</gadget>
<output>49</output>

<result>49</result>