Distribute building blocks to 10 children in the kindergarten. There are still some left over for each 3 yuan, but 4 yuan is not enough for each person. The remaining and the insufficient number are as many. How many building blocks are there?
给幼儿园的10个小朋友发积木，每人3块还剩下一些，每人4块又不够发，剩下的和不够的数量同样多，有多少块积木呢？
<gadget id="calculator">10 * 3</gadget>
<output>30</output>

<gadget id="calculator">10 * 4</gadget>
<output>40</output>

<gadget id="calculator">40 - 30</gadget>
<output>10</output>

<gadget id="calculator">10 / 2</gadget>
<output>5</output>

<gadget id="calculator">30 + 5</gadget>
<output>35</output>

<result>35</result>