import java.util.Scanner;

class Main {

	public static void main(String[] args) {

		int n, x;
		int i = 0, j = 0, k = 0;
		int count = 0;
		Scanner stdIn = new Scanner(System.in);

		boolean flag = true;
		while (flag) {
			n = stdIn.nextInt();
			x = stdIn.nextInt();

			if (n == 0 && x == 0) {
				flag = false;
				break;
			}

			count = 0;
			for (i = 1; i < n; i++) {
				for (j = i + 1; j < n; j++) {
					for (k = x - i - j; k > j; k--) {
						
						if (x == i + j + k && k <= n) {
							
							count++;
						} else {
							
						}
					}
				}

			}
			System.out.println(count);
		}
		stdIn.close();
	}
}
/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz