Structured Program II - How many ways?

Time Limit : 1 sec, Memory Limit : 65536 KB
Japanese version is here

How many ways?


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

  • You should select three integers from 1 to n without duplication.
  • 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