import java.util.Scanner;
import java.util.Arrays;

class Main{
	public static void main(String[] args){
		Scanner scanner = new Scanner(System.in);
		
		while(true){
			int n = scanner.nextInt();
			int x = scanner.nextInt();
			int count = 0;

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

			for(int i = 1; i < x/3; i++){
				for(int j = i+1; j < n; j++){
					int k = x - i - j;
					if(k > j && k <= n){
					    count ++;
					}
				}
			}
			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