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: Wrong Answer)

#1 から n までの数の中から、重複無しで３つの数を選びそれらの合計が x となる組み合わせの数を求める
while true
n,x=gets.split(" ").map(&:to_i) #n とx数字をとる
break if n==0 && x==0       #値ゼロの場合終了

count=0
for a in 1..n           #loopを始める
    for b in 1+1..n
        for c in b+1..n
            count += 1 if a+b+c==x
        end
    end
end
puts count
end