There is a series of numbers: 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, ... From the first number to the 2013 numbers in this series, how many odd numbers are there in total?
有一串数：1，1，2，3，5，8，13，21，34，55，…从第1个数起，到这串数的2013个数为止，共有多少个奇数．
<gadget id="calculator">2_013 / 3</gadget>
<output>671</output>

<gadget id="calculator">671 * 2</gadget>
<output>1_342</output>

<result>1_342</result>