import java.util.*;

public class Main{
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    int n,x,count;
    while((n = sc.nextInt()) != 0 | (x = sc.nextInt()) != 0){
      count=0;
      for(int i=1;i <= n-2;i++){
        for(int j=i+1;j <= n-1;j++){
          for(int k=j+1;k <= n;k++){
            if(i+j+k == x)count++;
          }
        }
      }
      System.out.println(count);
    }
    sc.close();
  }
}
 import java.util.*; util.* java public class Main{
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    int n,x,count;
    while((n = sc.nextInt()) != 0 | (x = sc.nextInt()) != 0){
      count=0;
      for(int i=1;i <= n-2;i++){
        for(int j=i+1;j <= n-1;j++){
          for(int k=j+1;k <= n;k++){
            if(i+j+k == x)count++;
          }
        }
      }
      System.out.println(count);
    }
    sc.close();
  }
} Main public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    int n,x,count;
    while((n = sc.nextInt()) != 0 | (x = sc.nextInt()) != 0){
      count=0;
      for(int i=1;i <= n-2;i++){
        for(int j=i+1;j <= n-1;j++){
          for(int k=j+1;k <= n;k++){
            if(i+j+k == x)count++;
          }
        }
      }
      System.out.println(count);
    }
    sc.close();
  } main {
    Scanner sc = new Scanner(System.in);
    int n,x,count;
    while((n = sc.nextInt()) != 0 | (x = sc.nextInt()) != 0){
      count=0;
      for(int i=1;i <= n-2;i++){
        for(int j=i+1;j <= n-1;j++){
          for(int k=j+1;k <= n;k++){
            if(i+j+k == x)count++;
          }
        }
      }
      System.out.println(count);
    }
    sc.close();
  } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int n n x x count; count while((n = sc.nextInt()) != 0 | (x = sc.nextInt()) != 0){
      count=0;
      for(int i=1;i <= n-2;i++){
        for(int j=i+1;j <= n-1;j++){
          for(int k=j+1;k <= n;k++){
            if(i+j+k == x)count++;
          }
        }
      }
      System.out.println(count);
    } (n = sc.nextInt()) != 0 | (x = sc.nextInt()) != 0 (n = sc.nextInt()) != 0 (n = sc.nextInt()) n sc.nextInt() sc.nextInt sc 0 (x = sc.nextInt()) != 0 (x = sc.nextInt()) x sc.nextInt() sc.nextInt sc 0 {
      count=0;
      for(int i=1;i <= n-2;i++){
        for(int j=i+1;j <= n-1;j++){
          for(int k=j+1;k <= n;k++){
            if(i+j+k == x)count++;
          }
        }
      }
      System.out.println(count);
    } count=0 count 0 for(int i=1;i <= n-2;i++){
        for(int j=i+1;j <= n-1;j++){
          for(int k=j+1;k <= n;k++){
            if(i+j+k == x)count++;
          }
        }
      } int i=1; int i=1; i 1 i <= n-2 i n-2 n 2 i++ i++ i {
        for(int j=i+1;j <= n-1;j++){
          for(int k=j+1;k <= n;k++){
            if(i+j+k == x)count++;
          }
        }
      } {
        for(int j=i+1;j <= n-1;j++){
          for(int k=j+1;k <= n;k++){
            if(i+j+k == x)count++;
          }
        }
      } for(int j=i+1;j <= n-1;j++){
          for(int k=j+1;k <= n;k++){
            if(i+j+k == x)count++;
          }
        } int j=i+1; int j=i+1; j i+1 i 1 j <= n-1 j n-1 n 1 j++ j++ j {
          for(int k=j+1;k <= n;k++){
            if(i+j+k == x)count++;
          }
        } {
          for(int k=j+1;k <= n;k++){
            if(i+j+k == x)count++;
          }
        } for(int k=j+1;k <= n;k++){
            if(i+j+k == x)count++;
          } int k=j+1; int k=j+1; k j+1 j 1 k <= n k n k++ k++ k {
            if(i+j+k == x)count++;
          } {
            if(i+j+k == x)count++;
          } if(i+j+k == x)count++; i+j+k == x i+j+k i+j+k i j k x count++ count System.out.println(count) System.out.println System.out System System.out count sc.close() sc.close sc String[] args args public class Main{
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    int n,x,count;
    while((n = sc.nextInt()) != 0 | (x = sc.nextInt()) != 0){
      count=0;
      for(int i=1;i <= n-2;i++){
        for(int j=i+1;j <= n-1;j++){
          for(int k=j+1;k <= n;k++){
            if(i+j+k == x)count++;
          }
        }
      }
      System.out.println(count);
    }
    sc.close();
  }
} public class Main{
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    int n,x,count;
    while((n = sc.nextInt()) != 0 | (x = sc.nextInt()) != 0){
      count=0;
      for(int i=1;i <= n-2;i++){
        for(int j=i+1;j <= n-1;j++){
          for(int k=j+1;k <= n;k++){
            if(i+j+k == x)count++;
          }
        }
      }
      System.out.println(count);
    }
    sc.close();
  }
} Main
import java.util.*;

public class Main{
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    int n,x,count;
    while((n = sc.nextInt()) != 0 | (x = sc.nextInt()) != 0){
      count=0;
      for(int i=1;i <= n-2;i++){
        for(int j=i+1;j <= n-1;j++){
          for(int k=j+1;k <= n;k++){
            if(i+j+k == x)count++;
          }
        }
      }
      System.out.println(count);
    }
    sc.close();
  }
}

