import java.util.Scanner;
 
public class Main {
 
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n, s, ans = 0;
 
        for(;;){
            n = sc.nextInt();
            s = sc.nextInt();
            if(n == 0 && s == 0) break;
            for(int i = 1; i < n; i++){
                for(int x = i+1; x < n; x++){
                    for(int y = x+1; y <= n; y++){
                        if(i+x+y==s) ans+=1;
                    }
                }
            }
            System.out.println(ans);
            ans = 0;
        }
    }
}
/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