Use n small cubes with an edge length of 1 to form a cuboid. When you look at it from an angle, you can see 3 faces. There are 231 small cubes that you can’t see. What is the minimum value of n?
用n个棱长为1的小正方体拼成一个长方体，从一个角度看过去看到3个面，没有看到的小正方体有231个，n最小是多少．
<gadget id="calculator">231 + 2</gadget>
<output>233</output>

<result>233</result>