The preschool class of Zhangji Elementary School buys a basket of oranges, distributes to 5 people and ends up with 2, distributes to 7 people and ends up with 2, distributes to 9 people and still has 2, how many oranges should the preschool buy at least?
张集小学学前班买来一筐橙子，分给5个人最后余2个，分给7人最后余2个，分给9人也余2个，学前班最少买来多少个橙子？
<gadget id="calculator">5 * 7 * 9</gadget>
<output>315</output>

<gadget id="calculator">315 + 2</gadget>
<output>317</output>

<result>317</result>