There is a rectangle with 420 small squares in length and 240 small squares in width. If the vertex of each small square is called a grid point, how many grid points (including both ends of the diagonal line) pass through the diagonal line connecting the rectangle.
有一个长方形，长有420个小方格，宽有240个小方格．如果把每个小方格的顶点称为格点，连接这个长方形的对角线共经过多少个格点(包括对角线两端)．
<gadget id="calculator">420 / 7</gadget>
<output>60</output>

<gadget id="calculator">60 + 1</gadget>
<output>61</output>

<result>61</result>