import java.util.*;

public class Main{
	public static void main(String[] args){

		Scanner scan = new Scanner(System.in);
		List<Integer> listN = new ArrayList<Integer>();
		List<Integer> listX = new ArrayList<Integer>();
		for(;;){
			int n = scan.nextInt();
			int x = scan.nextInt();
			if((n == 0) && (x == 0)){
				break;
			}
			listN.add(n);
			listX.add(x);
		}

		for(int i = 0; i < listN.size(); i++){
			int n = listN.get(i);
			int x = listX.get(i);
			int cnt = 0;
			for(int a = 1; a <= n; a++){
				for(int b = a + 1; b <= n; b++){
					for(int c = b + 1; c <= n; c++){
						int sum = a + b + c;
						if(sum == x){
							cnt++;
						}
					}
				}
			}
			System.out.println(cnt);
		}
	}
}
/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