import java.util.Scanner;
 
class Main{
  public static void main(String[] arg){
    int n, x;

    Scanner in = new Scanner(System.in);

    while(true){
        n = in.nextInt();
        x = in.nextInt();
        
        if(n == 0 && x == 0) break;

        int cnt = 0;
        
        for(int first = n; first > 0; first--){
            for(int second = 1; second < first; second++){
                int third = x - (first+second);
                if( first != second &&
                    third > 0 &&
                    third <= n &&
                    third != first &&
                    third != second){
                    // debug System.out.println("first = " + first + " second = " + second + " third = " + third);
                    cnt++;
                }
                    
            }
        }

        System.out.println(cnt/3);
    }

  }
}
/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