The school held a campus culture and art festival, and the sixth grade students signed up for the art group and calligraphy and painting group. It is known that (2/3) students participated in the art group, (5/12) students participated in the calligraphy and painting group, and 12 students participated in both groups. What is the total number of sixth grade students?
学校举行校园文化艺术节，六年级同学都报名参加了文艺组和书画组．已知有(2/3)的同学参加文艺组，(5/12)的同学参加书画组，其中12个同学两个小组都参加．六年级学生的总人数是多少人．
<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">5 / 12</gadget>
<output>5/12 = around 0.416667</output>

<gadget id="calculator">(5/12) - 1</gadget>
<output>-7/12 = around -0.583333</output>

<gadget id="calculator">(2/3) + (-7/12)</gadget>
<output>1/12 = around 0.083333</output>

<gadget id="calculator">12 / (1/12)</gadget>
<output>144</output>

<result>144</result>