Saw the cube that is colored on all sides into 27 small cubes of equal size, among them, the number of small cubes with exactly 1 side painted with color is denoted as a, and the number of small cubes with exactly 2 sides painted with color The number is recorded as b, the number of small cubes with exactly three sides painted with color is recorded as c, and the value of a-b+c is calculated.
将各面都涂有颜色的正方体锯成27个大小相等的小正方体，其中恰有1个面涂有颜色的小正方体的个数记为a，恰有2个面涂有颜色的小正方体的个数记为b，恰有三个面涂有颜色的小正方体的个数记为c，求a-b+c的值．
<gadget id="calculator">6 - 12</gadget>
<output>-6</output>

<gadget id="calculator">(-6) + 8</gadget>
<output>2</output>

<result>2</result>