There are 2004 boxes with small balls, arrange them in a row from left to right, and there are 30 small balls in every four adjacent boxes, if there are 7 small balls in box 201, box 462 There are 4 small balls in it, and there are 13 small balls in the No. 575 box, so how many small balls are in the rightmost box.
现有2004个放有小球的盒子，将它们从左到右排成一行，且每四个相邻的盒子里共有30个小球，如果201号盒子里有7个小球，462号盒子里面有4个小球，575号盒子里有13个小球，那么最右边的盒子里有多少个小球．
<gadget id="calculator">30 - 7 - 4 - 13</gadget>
<output>6</output>

<result>6</result>