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 JavaScript (judge verdict: Accepted)

process.stdin.resume();
process.stdin.setEncoding("utf8");

const reader = require("readline").createInterface({
  input: process.stdin,
  output: process.stdout,
});

const lines = [];

reader.on("line", (line) => {
  lines.push(line);
});

reader.on("close", () => {
  for (let l = 0; l < lines.length; l++) {
    const [n, x] = parseLine(lines[l]);
    if (!n && !x) break;
    let count = 0;
    for (let i = Math.min(x - 1, n); i > 2; i--) {
      for (let j = i - 1; j > 1; j--) {
        let k = x - (i + j);
        if (k > 0 && k < j) count++;
      }
    }
    console.log(count);
  }
});

function parseLine(s) {
  return s.split(" ").map((s) => Number(s));
}