The school set up calligraphy and robot interest groups. Class 31 had 29 people participating in the calligraphy group, 32 people participating in the robot group, and 16 people participating in both interest groups. How many students are there in Class 3 and Class 1?
学校开设书法和机器人兴趣小组，三1班参加书法小组的有29人，参加机器人小组的有32人，两个兴趣小组都参加的有16人．三1班共有学生多少人人．
<gadget id="calculator">32 - 16</gadget>
<output>16</output>

<gadget id="calculator">29 + 16</gadget>
<output>45</output>

<result>45</result>