import java.util.Scanner;

class Main {
  public static void main(String[] args) {
    Scanner in = new Scanner(System.in);
    int n, sum;
    
    while(in.hasNext()) {
      int count = 0;
      n = in.nextInt();
      sum = in.nextInt();
      if (n == 0 && sum == 0) return;
      
      for (int i = 1; i < n -1; i++) {
        for (int j = i + 1; j < n; j++) {
          int rest = sum - i -j;
          if (rest > j && rest <= n) 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