public class RandomWalker
{
    public static void main(String[] args)
    {
        int r = Integer.parseInt(args[0]);

        int xCoordinate = 0;
        int yCoordinate = 0;
        int steps = 0;

        System.out.println("(" + xCoordinate + ", " + yCoordinate + ")" );
        
        while(Math.abs(xCoordinate) + Math.abs(yCoordinate) < r)
        {
            if(Math.random() <= 0.25)       xCoordinate += 1;
            else if (Math.random() <= 0.50) xCoordinate -= 1;
            else if (Math.random() <= 0.75) yCoordinate += 1;
            else                            yCoordinate -= 1;

            System.out.println("(" + xCoordinate + ", " + yCoordinate + ")" );
            steps++; 
        }
        System.out.println("steps = " + steps);
    }
}