The students went on a spring outing. There were 78 people who brought water bottles, 77 people who brought fruits, and 48 people who brought both water bottles and fruits. Each person brought at least one kind. How many students are there in the spring outing?
同学们去春游，带水壶的有78人，带水果的有77人，既带水壶又带水果的有48人，每人至少带一种．参加春游的同学一共有多少人？
<gadget id="calculator">78 - 48</gadget>
<output>30</output>

<gadget id="calculator">77 + 30</gadget>
<output>107</output>

<result>107</result>