import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner scan=new Scanner(System.in);
		while(true) {
			int n=scan.nextInt();
			int a=scan.nextInt();
			int sum=0,count=0;
			for(int i=1;i<=n;i++) {
				for(int j=2;j<=n;j++) {
					for(int k=3;k<=n;k++) {
						if(i == j || j == k || i == k) {
						}else {
							sum = i+j+k;
						if (sum == a && i<j && j<k) {
							count += 1;
						}
						}
					}
				}
			}
			if(n==0 && a==0) {
				break;
			}
			System.out.println(count);
}
		scan.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