import java.util.Scanner;
import javax.sound.midi.SysexMessage;
  
public class Main{      
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        for(int l = 0;l<100;l++){
            String str = sc.nextLine();
            String str2[] = str.split(" ");
            int n = Integer.parseInt(str2[0]);
            int x = Integer.parseInt(str2[1]);
            if(n==0&&x==0)
                break;
            int count = 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)
                            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