For students of class 11-12 (age 16+)
There are 10 small boxes with 1,2,...,10 chips and 2 large empty boxes. Each turn B will choose one of the two large boxes and A chooses a nonempty small box and puts the chips in it into the said box. After ten turns all small boxes are empty and A chooses one of the large boxes and receives the chips in it. How many chips can A get at least?