There is a balance with only two weights of 5 grams and 30 grams. To divide 600 grams of salt into three equal parts, how many times must the balance be weighed at least.
有一架天平，只有5克和30克两个砝码，要把600克盐分成三等份，最少要运用天平称多少次．
<gadget id="calculator">3 + 1 + 1</gadget>
<output>5</output>

<result>5</result>