Problem:
How many ways?

Write a program which identifies the number of combinations of three integers which satisfy the following conditions:

You should select three distinct integers from 1 to n.

A total sum of the three integers is x.

For example, there are two combinations for n = 5 and x = 9.

1 + 3 + 5 = 9

2 + 3 + 4 = 9

Input

The input consists of multiple datasets. For each dataset, two integers n and x are given in a line.

The input ends with two zeros for n and x respectively. Your program should not process for these terminal symbols.

Constraints

3 ≤ n ≤ 100

0 ≤ x ≤ 300

Output

For each dataset, print the number of combinations in a line.

Sample Input

5 9
0 0

Sample Output

2

Note

      解説

Solution in Ruby (judge verdict: Accepted)

def array_integer(a)
	0.upto(a.count) {|x|
		a[x] = a[x].to_i
	}
	return a
end

eof = false

until eof do
	n,x = array_integer(STDIN.gets.split(" "))
	
	if n == 0 && x == 0 then
		eof = true
		break
	end

	if x < 6 then
		print "0\n"
		next
	end

	answer_num = 0
	
	
	1.upto(n-2) {|i|
		if ((i * 3) + 2) > x then
			break
		end
		(i+1).upto(n-1) {|j|
			if (i + (j * 2) + 1) > x then
				break
			end
			(j+1).upto(n) {|k|
				if i + j + k > x then
					break
				elsif i + j + k == x then
					answer_num += 1
				end
			}
		}
	}
	print answer_num, "\n"
end