The teacher asked the students to shake hands every two people. Given that there are 10 girls and 12 boys in the class, how many handshakes are there in total?
老师让同学们每两个人都握一次手．已知班上有10名女生，12名男生，那么，一共要握多少次手？
<gadget id="calculator">12 - 1</gadget>
<output>11</output>

<gadget id="calculator">10 + 11</gadget>
<output>21</output>

<gadget id="calculator">10 + 12</gadget>
<output>22</output>

<gadget id="calculator">22 / 2</gadget>
<output>11</output>

<gadget id="calculator">21 * 11</gadget>
<output>231</output>

<result>231</result>