x = 0.0;
y = 0.0;
dist = 0.0;
count = 1;
N = 7; 
while (count < N) do
	c1 = unifReal(0.0, 1.0);
	c2 = unifReal(0.0, 1.0);
	c3 = unifReal(0.0, 1.0);
	r1 = unifReal(0.0, 1.0);
	if (x >= 0.0) 
	then
		if (y >= 0.0)
		then
			if (c1 <= 0.5)
			then
				if (c2 <= 0.5)
				then
					x = x + r1;
					dist = dist + r1
				else
                                        y = y + r1;
                                        dist = dist + r1
				end
			else
				if (c3 <= 0.5)
                                then
                                        x = x - r1;
                                        dist = dist - r1 
                                else
                                        y = y - r1;
                                        dist = dist - r1 
                                end 
			end
		else
			if (c1 <= 0.5)
                        then
                                if (c2 <= 0.5)
                                then
                                        x = x + r1;
                                        dist = dist + r1
                                else
                                        y = y + r1;
                                        dist = dist - r1
                                end
                        else
                                if (c3 <= 0.5)
                                then
                                        x = x - r1;
                                        dist = dist - r1
                                else
                                        y = y - r1;
                                        dist = dist + r1
                                end
                        end
		end
	else
		if (y >= 0.0)
                then
                        if (c1 <= 0.5)
                        then
                                if (c2 <= 0.5)
                                then
                                        x = x - r1;
                                        dist = dist + r1
                                else
                                        y = y + r1;
                                        dist = dist + r1
                                end
                        else
                                if (c3 <= 0.5)
                                then
                                        x = x + r1;
                                        dist = dist - r1
                                else
                                        y = y - r1;
                                        dist = dist - r1
                                end
                        end
                else
                        if (c1 <= 0.5)
                        then
                                if (c2 <= 0.5)
                                then
                                        x = x - r1;
				        dist = dist + r1
				else
                                        y = y + r1;
                                        dist = dist - r1
                                end
                        else
                                if (c3 <= 0.5)
                                then
                                        x = x + r1;
                                        dist = dist - r1
                                else
                                        y = y - r1;
                                        dist = dist + r1
                                end
                        end
                end
	end;
	count = count + 1
end;
estimateProb(dist <= -4.0);
estimateProb(dist <= -3.0);
estimateProb(dist <= -2.0);
estimateProb(dist <= -1.0);
estimateProb(dist <= 0.0);
estimateProb(dist <= 1.0);
estimateProb(dist <= 2.0);
estimateProb(dist <= 3.0);
estimateProb(dist <= 4.0)