Wang Tao added consecutive natural numbers 1, 2, 3, ... one by one until a certain natural number was added, and a wrong result was obtained because a natural number was omitted in the calculation. 2012. So, what is the natural number he left out?
王涛将连续的自然数1，2，3，…逐个相加，一直加到某个自然数为止，由于计算时漏加了一个自然数而得到错误的结果2012．那么，他漏加的自然数是多少．
<gadget id="calculator">2_016 - 2_012</gadget>
<output>4</output>

<result>4</result>