There are 2018 bins along a large circle, and either a white ball or a black ball is alternately put in each bin.
(a) Choose 2 out of the 2018 balls (not bins).
(b) For each chosen ball; If it is white, move it clockwise to the next bin; if black, move it counterclockwise to the next.
By repeating (a) and (b), can we gather all of the balls in one bin?
