From the natural numbers of 1-2014, how many numbers are taken at most, so that the difference between no two numbers in these numbers is a multiple of 3.
从1-2014的自然数中，最多取出多少个数，使得这些数中没有两个数的差是3的倍数．
<gadget id="calculator">4 - 1</gadget>
<output>3</output>

<result>3</result>