Then, each person can borrow up to three books.

The possibility of borrowing books is: C( 1, 4)=4.

The possibility of borrowing two books is as follows: c (2,4) = 6 If you don't choose one book, plus both books are selected from the same one, it is 10.

The possibility of borrowing three books is as follows: if you choose one book in ABCD, C (3,4) = 4; If you choose two copies, choose 1, which is a (2,4)12; If only three copies are selected in 1, it is C( 1, 4)=4 * *.

So a * * * is 4+ 10+20=34.

Then m must be at least 35 to achieve the meaning of the problem. It is wrong that the analysis upstairs is incomplete.