If one number is removed from n consecutive positive integers from 1 to n, the average of the remaining n-1 numbers is 35 (7/17). What is the removed number?
从1～n这n个连续正整数中去掉一个数，则剩下的n-1个数的平均数为35(7/17)，求去掉的数是多少？
<gadget id="calculator">69 * 70</gadget>
<output>4_830</output>

<gadget id="calculator">4_830 / 2</gadget>
<output>2_415</output>

<gadget id="calculator">602 / 17</gadget>
<output>602/17 = around 35.411765</output>

<gadget id="calculator">68 * (602/17)</gadget>
<output>2_408</output>

<gadget id="calculator">2_415 - 2_408</gadget>
<output>7</output>

<result>7</result>