import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);

        while (true) {
            int n = scan.nextInt();
            int x = scan.nextInt();
            if (n == 0 && x == 0) break;
            int count = 0;


            for (int i = 1; i < n; ++i) {
                for (int j = i; j < n; ++j) {
                    if (i == j) continue;
                    int num = x - (i + j);
                    if (num < 1) break;
                    if (num < j) break;
                    if (i != num && j != num && num <= n) count++;
                    num = 0;
                }
            }
            System.out.println(count);
        }
    }
}
/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