
import java.util.Scanner;

public class Main {
    public static void main(String... args) {
        Scanner sc = new Scanner(System.in);
        while(true) {
        int n = sc.nextInt();
        int x = sc.nextInt();
            if(n == 0 && x == 0) break;
        int s = 0;
        for(int i = 1; i <= n; i++) {
            for(int j = i + 1; j <= n; j++) {
                for(int k = j + 1; k <= n; k++) {
                    if(i + j + k == x) s++;
                }
            }
        }
        System.out.println(s);
        }
    }
}

/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