There are 50 students in the class, and the books are distributed to everyone. At least how many books must be taken to ensure that at least one student can get two or more books.
班上有50名学生，将书分给大家，至少要拿多少本，才能保证至少有一个学生能得到两本或两本以上的书．
<gadget id="calculator">50 + 1</gadget>
<output>51</output>

<result>51</result>