import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;

public class Main {

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);

		List<int[]> nxs = new ArrayList<>();

		while(true) {
			int n = sc.nextInt();
			int x = sc.nextInt();

			if(n == 0) break;
			int[] nx = new int[] {n, x};
			nxs.add(nx);
		}
		sc.close();

		for (int[] nx : nxs) {
			int count = check(nx[0], nx[1]);
			System.out.println(count);
		}

	}

	private static int check(int n, int x) {

		if(n > x-3) n = x-3;

		int ans = 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) ans++;
				}
			}
		}
		return ans;
	}
} import java.util.ArrayList; ArrayList java.util import java.util.List; List java.util import java.util.Scanner; Scanner java.util public class Main {

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);

		List<int[]> nxs = new ArrayList<>();

		while(true) {
			int n = sc.nextInt();
			int x = sc.nextInt();

			if(n == 0) break;
			int[] nx = new int[] {n, x};
			nxs.add(nx);
		}
		sc.close();

		for (int[] nx : nxs) {
			int count = check(nx[0], nx[1]);
			System.out.println(count);
		}

	}

	private static int check(int n, int x) {

		if(n > x-3) n = x-3;

		int ans = 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) ans++;
				}
			}
		}
		return ans;
	}
} Main public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);

		List<int[]> nxs = new ArrayList<>();

		while(true) {
			int n = sc.nextInt();
			int x = sc.nextInt();

			if(n == 0) break;
			int[] nx = new int[] {n, x};
			nxs.add(nx);
		}
		sc.close();

		for (int[] nx : nxs) {
			int count = check(nx[0], nx[1]);
			System.out.println(count);
		}

	} main {

		Scanner sc = new Scanner(System.in);

		List<int[]> nxs = new ArrayList<>();

		while(true) {
			int n = sc.nextInt();
			int x = sc.nextInt();

			if(n == 0) break;
			int[] nx = new int[] {n, x};
			nxs.add(nx);
		}
		sc.close();

		for (int[] nx : nxs) {
			int count = check(nx[0], nx[1]);
			System.out.println(count);
		}

	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) List<int[]> nxs = new ArrayList<>(); nxs new ArrayList<>() while(true) {
			int n = sc.nextInt();
			int x = sc.nextInt();

			if(n == 0) break;
			int[] nx = new int[] {n, x};
			nxs.add(nx);
		} true {
			int n = sc.nextInt();
			int x = sc.nextInt();

			if(n == 0) break;
			int[] nx = new int[] {n, x};
			nxs.add(nx);
		} 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; int[] nx = new int[] {n, x}; nx new int[] {n, x} nxs.add(nx) nxs.add nxs nx sc.close() sc.close sc for (int[] nx : nxs) {
			int count = check(nx[0], nx[1]);
			System.out.println(count);
		} int[] nx nxs {
			int count = check(nx[0], nx[1]);
			System.out.println(count);
		} {
			int count = check(nx[0], nx[1]);
			System.out.println(count);
		} int count = check(nx[0], nx[1]); count check(nx[0], nx[1]) check nx[0] nx 0 nx[1] nx 1 System.out.println(count) System.out.println System.out System System.out count String[] args args private static int check(int n, int x) {

		if(n > x-3) n = x-3;

		int ans = 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) ans++;
				}
			}
		}
		return ans;
	} check {

		if(n > x-3) n = x-3;

		int ans = 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) ans++;
				}
			}
		}
		return ans;
	} if(n > x-3) n = x-3; n > x-3 n x-3 x 3 n = x-3 n x-3 x 3 int ans = 0; ans 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) ans++;
				}
			}
		} 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) ans++;
				}
			}
		} {
			for (int j = i+1; j <= n-1; j++) {
				for (int k = j+1; k <= n; k++) {
					if(i + j + k == x) ans++;
				}
			}
		} for (int j = i+1; j <= n-1; j++) {
				for (int k = j+1; k <= n; k++) {
					if(i + j + k == x) ans++;
				}
			} 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) ans++;
				}
			} {
				for (int k = j+1; k <= n; k++) {
					if(i + j + k == x) ans++;
				}
			} for (int k = j+1; k <= n; k++) {
					if(i + j + k == x) ans++;
				} 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) ans++;
				} {
					if(i + j + k == x) ans++;
				} if(i + j + k == x) ans++; i + j + k == x i + j + k i + j + k i j k x ans++ ans return ans; ans int n n int x x public class Main {

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);

		List<int[]> nxs = new ArrayList<>();

		while(true) {
			int n = sc.nextInt();
			int x = sc.nextInt();

			if(n == 0) break;
			int[] nx = new int[] {n, x};
			nxs.add(nx);
		}
		sc.close();

		for (int[] nx : nxs) {
			int count = check(nx[0], nx[1]);
			System.out.println(count);
		}

	}

	private static int check(int n, int x) {

		if(n > x-3) n = x-3;

		int ans = 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) ans++;
				}
			}
		}
		return ans;
	}
} public class Main {

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);

		List<int[]> nxs = new ArrayList<>();

		while(true) {
			int n = sc.nextInt();
			int x = sc.nextInt();

			if(n == 0) break;
			int[] nx = new int[] {n, x};
			nxs.add(nx);
		}
		sc.close();

		for (int[] nx : nxs) {
			int count = check(nx[0], nx[1]);
			System.out.println(count);
		}

	}

	private static int check(int n, int x) {

		if(n > x-3) n = x-3;

		int ans = 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) ans++;
				}
			}
		}
		return ans;
	}
} Main
import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;

public class Main {

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);

		List<int[]> nxs = new ArrayList<>();

		while(true) {
			int n = sc.nextInt();
			int x = sc.nextInt();

			if(n == 0) break;
			int[] nx = new int[] {n, x};
			nxs.add(nx);
		}
		sc.close();

		for (int[] nx : nxs) {
			int count = check(nx[0], nx[1]);
			System.out.println(count);
		}

	}

	private static int check(int n, int x) {

		if(n > x-3) n = x-3;

		int ans = 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) ans++;
				}
			}
		}
		return ans;
	}
}