while (n, x = gets.split.map(&:to_i)) != [0, 0] do

	count = 0
	for i in 1..n do
		for j in (i+1)..n do
			for k in (j+1)..n do
				if  i + j + k == x then
					count += 1
				end
			end		
		end
	end

	puts count

end