An urn contains 2 black bells end 2 white bells. At time n a, ball is selected at random from the um, and the color is noted. If the number of balls of this color is net less thsn the number of halls of the ether color, then the bell is put back in the urn; otherwise, the ball is left out. Let X(s} be the number of bleak balls in the urn after nth drew. Does this random sequence converge