import java.util.*;

public class Main {
	public static void main(String[] args) {
		@SuppressWarnings("resource")
		Scanner sc = new Scanner(System.in);
		while (true) {
			int n = sc.nextInt();
			int x = sc.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.*; util.* java public class Main {
	public static void main(String[] args) {
		@SuppressWarnings("resource")
		Scanner sc = new Scanner(System.in);
		while (true) {
			int n = sc.nextInt();
			int x = sc.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) {
		@SuppressWarnings("resource")
		Scanner sc = new Scanner(System.in);
		while (true) {
			int n = sc.nextInt();
			int x = sc.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 {
		@SuppressWarnings("resource")
		Scanner sc = new Scanner(System.in);
		while (true) {
			int n = sc.nextInt();
			int x = sc.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);
		}
	} @SuppressWarnings("resource")
		Scanner sc = new Scanner(System.in); sc new Scanner(System.in) while (true) {
			int n = sc.nextInt();
			int x = sc.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 = sc.nextInt();
			int x = sc.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 = sc.nextInt(); n sc.nextInt() sc.nextInt sc int x = sc.nextInt(); x sc.nextInt() sc.nextInt sc 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++; 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++; 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++; 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) {
		@SuppressWarnings("resource")
		Scanner sc = new Scanner(System.in);
		while (true) {
			int n = sc.nextInt();
			int x = sc.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) {
		@SuppressWarnings("resource")
		Scanner sc = new Scanner(System.in);
		while (true) {
			int n = sc.nextInt();
			int x = sc.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.*;

public class Main {
	public static void main(String[] args) {
		@SuppressWarnings("resource")
		Scanner sc = new Scanner(System.in);
		while (true) {
			int n = sc.nextInt();
			int x = sc.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);
		}
	}
}