import java.util.*;
public class Main {
public static void main(String[] args){
Scanner sc = new Scanner(System.in);
while(true){
    int n=Integer.parseInt(sc.next());
    int x=Integer.parseInt(sc.next());
    if(n==0&&x==0)break;
int count=0;
for(int i=1;i<=n;i++){
for(int j=1;j<=n;j++){
    if(i==j)break;
for(int k=1;k<=n;k++){
    if(j==k)break;
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