There are 3 classes A, B, and C in the fourth grade in a certain school. There are 100 students in Class A and Class B, 101 students in Class B and Class C, and 97 students in Class A and Class C. How many people are there in Class B?
某学校四年级有甲、乙、丙3个班，甲班和乙班共有100人，乙班和丙班共有101人，甲班和丙班共有97人．乙班有多少人．
<gadget id="calculator">101 - 97</gadget>
<output>4</output>

<gadget id="calculator">100 + 4</gadget>
<output>104</output>

<gadget id="calculator">104 / 2</gadget>
<output>52</output>

<result>52</result>