Time Limit : sec, Memory Limit : KB
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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