When there is a thief in my class who steals money from the other students bags. I would keep my money more safe with me take extra care of my objects and money. To solve this issue I would try to find the thief myself and if even though I won't able to find the student, I would complain the issue to principle sir and then he will do strict checking on every student and if the thief is caught, I would request sir to give him a very tough punishment so he doesn't repeats it again.