import java.util.Scanner;
public class Main {
    public static void main(String[]args){
        Scanner sc = new Scanner(System.in);
        while(true){
            int n,x,a=0;
            n = sc.nextInt();
            x = sc.nextInt();
            if(n==0&&x==0)break;
            for(int i=1;i<n-1;i++){
                for(int j=i+1;j<n;j++){
                    int c = x - i - j;
                    if(c>j&&c<=n){
                        a++;
                    }
                }
            }
            System.out.println(a);
        }
    }
}

/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