The fourth grade organized a spring outing. There were 252 students in total. The first group went to 123 people, and the second group went to 77 people. How many people are left?
四年级组织春游，一共252人，第一批去了123人，第二批去了77人，这是还剩下几人？
<gadget id="calculator">123 + 77</gadget>
<output>200</output>

<gadget id="calculator">252 - 200</gadget>
<output>52</output>

<result>52</result>