There are 51 students in a certain class. Everyone shakes hands with other students once when they graduate. How many handshakes did the class have in total?
某班有51个同学，毕业时每人都要和其他同学握一次手，那么这个班共握了多少次手？
<gadget id="calculator">51 - 1</gadget>
<output>50</output>

<gadget id="calculator">50 / 2</gadget>
<output>25</output>

<gadget id="calculator">51 * 25</gadget>
<output>1_275</output>

<result>1_275</result>