import java.util.Scanner;

public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        
        while(true){
            int sum = 0;
            int n = sc.nextInt();
            int x = sc.nextInt();
            
            if(n == 0){
                break;
            }
            
            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){
                            sum++;
                        }
                    }
                }
            }
            
            System.out.println(sum);
        }
    }
}
 import java.util.Scanner; Scanner java.util public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        
        while(true){
            int sum = 0;
            int n = sc.nextInt();
            int x = sc.nextInt();
            
            if(n == 0){
                break;
            }
            
            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){
                            sum++;
                        }
                    }
                }
            }
            
            System.out.println(sum);
        }
    }
} Main public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        
        while(true){
            int sum = 0;
            int n = sc.nextInt();
            int x = sc.nextInt();
            
            if(n == 0){
                break;
            }
            
            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){
                            sum++;
                        }
                    }
                }
            }
            
            System.out.println(sum);
        }
    } main {
        Scanner sc = new Scanner(System.in);
        
        while(true){
            int sum = 0;
            int n = sc.nextInt();
            int x = sc.nextInt();
            
            if(n == 0){
                break;
            }
            
            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){
                            sum++;
                        }
                    }
                }
            }
            
            System.out.println(sum);
        }
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) while(true){
            int sum = 0;
            int n = sc.nextInt();
            int x = sc.nextInt();
            
            if(n == 0){
                break;
            }
            
            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){
                            sum++;
                        }
                    }
                }
            }
            
            System.out.println(sum);
        } true {
            int sum = 0;
            int n = sc.nextInt();
            int x = sc.nextInt();
            
            if(n == 0){
                break;
            }
            
            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){
                            sum++;
                        }
                    }
                }
            }
            
            System.out.println(sum);
        } int sum = 0; sum 0 int n = sc.nextInt(); n sc.nextInt() sc.nextInt sc int x = sc.nextInt(); x sc.nextInt() sc.nextInt sc if(n == 0){
                break;
            } n == 0 n 0 {
                break;
            } break; 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){
                            sum++;
                        }
                    }
                }
            } int i = 1; int i = 1; i 1 i <= n i n i++ i++ i {
                for(int j = i + 1; j <= n; j++){
                    for(int k = j + 1; k <= n; k++){
                        if(i + j + k == x){
                            sum++;
                        }
                    }
                }
            } {
                for(int j = i + 1; j <= n; j++){
                    for(int k = j + 1; k <= n; k++){
                        if(i + j + k == x){
                            sum++;
                        }
                    }
                }
            } for(int j = i + 1; j <= n; j++){
                    for(int k = j + 1; k <= n; k++){
                        if(i + j + k == x){
                            sum++;
                        }
                    }
                } int j = i + 1; int j = i + 1; j i + 1 i 1 j <= n j n j++ j++ j {
                    for(int k = j + 1; k <= n; k++){
                        if(i + j + k == x){
                            sum++;
                        }
                    }
                } {
                    for(int k = j + 1; k <= n; k++){
                        if(i + j + k == x){
                            sum++;
                        }
                    }
                } for(int k = j + 1; k <= n; k++){
                        if(i + j + k == x){
                            sum++;
                        }
                    } 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){
                            sum++;
                        }
                    } {
                        if(i + j + k == x){
                            sum++;
                        }
                    } if(i + j + k == x){
                            sum++;
                        } i + j + k == x i + j + k i + j + k i j k x {
                            sum++;
                        } sum++ sum System.out.println(sum) System.out.println System.out System System.out sum String[] args args public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        
        while(true){
            int sum = 0;
            int n = sc.nextInt();
            int x = sc.nextInt();
            
            if(n == 0){
                break;
            }
            
            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){
                            sum++;
                        }
                    }
                }
            }
            
            System.out.println(sum);
        }
    }
} public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        
        while(true){
            int sum = 0;
            int n = sc.nextInt();
            int x = sc.nextInt();
            
            if(n == 0){
                break;
            }
            
            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){
                            sum++;
                        }
                    }
                }
            }
            
            System.out.println(sum);
        }
    }
} Main
import java.util.Scanner;

public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        
        while(true){
            int sum = 0;
            int n = sc.nextInt();
            int x = sc.nextInt();
            
            if(n == 0){
                break;
            }
            
            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){
                            sum++;
                        }
                    }
                }
            }
            
            System.out.println(sum);
        }
    }
}

