Lost Property

In school, when students lose their own labcoats, usually the teachers keep hold of them and let other students use them, until the student who lost the labcoat initially comes back and reclaims it. Sometimes the lost labcoat, if it has been unclaimed for a long time, will be given to another student. Can the student take it? If it is returned to the school, but in a condition worse than it was when it was given to him, what is the duty of the student?

You do not have to do anything, and if it is given to you, you can take it.