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)

n = -1
x = -1
while n != 0 || x != 0
n,x = gets.split.map(&:to_i)
ans = 0
  if  n == 0 && x == 0
  elsif
    for a in 1..n do
      for b in 1..n do
        for c in 1..n do
          if a + b + c == x && a != b && b != c && c != a
            ans += 1
          end
        end
      end    
    end
    p ans/6
  end  
end