There is a series of numbers, 1, 1994, 1993, 1, 1992, ..., starting from the third number, each number is the difference between the first two numbers and the smaller number, then what is the 2004th number.
有一列数，1，1994，1993，1，1992，…，从第三个数起，每一个数都是它前面两个数中大数减小数的差，那么第2004个数是多少．
<gadget id="calculator">2_004 / 3</gadget>
<output>668</output>

<gadget id="calculator">668 - 1</gadget>
<output>667</output>

<gadget id="calculator">667 * 2</gadget>
<output>1_334</output>

<gadget id="calculator">1_993 - 1_334</gadget>
<output>659</output>

<result>659</result>