An integer greater than 300 but less than 400 is a multiple of 3, 5, and 7 at the same time. What is this number?
一个大于300又小于400的整数，同时是3、5、7的倍数，这个数是多少．
<gadget id="calculator">3 * 5 * 7</gadget>
<output>105</output>

<gadget id="calculator">105 * 3</gadget>
<output>315</output>

<result>315</result>