import java.util.*;
 
public class Main {
 
    public static void main(String[] args) {
        int n, x, count = 0;
        boolean flag = false;
        Scanner sc = new Scanner(System.in);
        while (true) {
            n = sc.nextInt();
            x = sc.nextInt();
            if (n == 0 && x == 0)
                break;
            for (int i = 1; i <= n; i++) {
                for (int j = 1; j <= n; j++) {
                    for (int k = 1; k <= n; k++) {
                        if (i + j + k == x)
                            flag = true;
                        if (i == j || j == k || k == i)
                            flag = false;
                        if (flag) {
                            count++;
                        }
                        flag = false;
                    }
                }
            }
            System.out.println(count / 6);
            count = 0;
        }
    }
}
/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