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));
}

