Two robots land with their parachutes on an infinite one-dimensional number line. * They both release their parachutes as soon as they land and start moving. * They are allowed only to make use of the following functions. * I. moveLeft() // robot moves to left by 1 unit in 1 unit time * II. moveRight() // robot moves to right by 1 unit in 1 unit time * III. noOperation() // robot does not move and takes 1 unit time * IV. onTopOfParachute() // returns true if the robot is standing on top of either of the parachute, else false * V. didWeMeet() // returns true if the robot meets to the other robot, else false