import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        while (true) {
            int n = scanner.nextInt();
            int x = scanner.nextInt();
            if (n == 0 && x == 0) break;
            int 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);
        }
    }
} import java.util.Scanner; Scanner java.util public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        while (true) {
            int n = scanner.nextInt();
            int x = scanner.nextInt();
            if (n == 0 && x == 0) break;
            int 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);
        }
    }
} Main public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        while (true) {
            int n = scanner.nextInt();
            int x = scanner.nextInt();
            if (n == 0 && x == 0) break;
            int 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);
        }
    } main {
        Scanner scanner = new Scanner(System.in);
        while (true) {
            int n = scanner.nextInt();
            int x = scanner.nextInt();
            if (n == 0 && x == 0) break;
            int 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);
        }
    } Scanner scanner = new Scanner(System.in); scanner new Scanner(System.in) while (true) {
            int n = scanner.nextInt();
            int x = scanner.nextInt();
            if (n == 0 && x == 0) break;
            int 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);
        } true {
            int n = scanner.nextInt();
            int x = scanner.nextInt();
            if (n == 0 && x == 0) break;
            int 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);
        } int n = scanner.nextInt(); n scanner.nextInt() scanner.nextInt scanner int x = scanner.nextInt(); x scanner.nextInt() scanner.nextInt scanner if (n == 0 && x == 0) break; n == 0 && x == 0 n == 0 n 0 x == 0 x 0 break; int 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 String[] args args public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        while (true) {
            int n = scanner.nextInt();
            int x = scanner.nextInt();
            if (n == 0 && x == 0) break;
            int 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);
        }
    }
} public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        while (true) {
            int n = scanner.nextInt();
            int x = scanner.nextInt();
            if (n == 0 && x == 0) break;
            int 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);
        }
    }
} Main
import java.util.Scanner;

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