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 x=scan.nextInt();

		if(n==0&&x==0)break;

		System.out.println(return_num(n,x));

		}

		scan.close();
	}

	public static int return_num(int n, int x){
		int num=0;

		for(int i=1;i<n-1;i++){
			for(int j=i+1;j<n;j++){
				for(int k=j+1;k<n+1;k++){
					if(i+j+k==x)num++;
				}
			}
		}


	return num;
			}


}
/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