import java.util.Arrays;
import java.util.HashMap;
import java.util.Map;
import java.util.Scanner;

public class Main {
	
	public static void main(String args[]) {
		Scanner sc = new Scanner(System.in);

		while (true) {
			final int n = sc.nextInt();
			final int x = sc.nextInt();
			
			if(n == 0 && x == 0){
				break;
			}
			
			int count = 0;
			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){
							count++;
						}
					}
				}
			}
			
			System.out.println(count);
		}
	}

} import java.util.Arrays; Arrays java.util import java.util.HashMap; HashMap java.util import java.util.Map; Map java.util import java.util.Scanner; Scanner java.util public class Main {
	
	public static void main(String args[]) {
		Scanner sc = new Scanner(System.in);

		while (true) {
			final int n = sc.nextInt();
			final int x = sc.nextInt();
			
			if(n == 0 && x == 0){
				break;
			}
			
			int count = 0;
			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){
							count++;
						}
					}
				}
			}
			
			System.out.println(count);
		}
	}

} Main public static void main(String args[]) {
		Scanner sc = new Scanner(System.in);

		while (true) {
			final int n = sc.nextInt();
			final int x = sc.nextInt();
			
			if(n == 0 && x == 0){
				break;
			}
			
			int count = 0;
			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){
							count++;
						}
					}
				}
			}
			
			System.out.println(count);
		}
	} main {
		Scanner sc = new Scanner(System.in);

		while (true) {
			final int n = sc.nextInt();
			final int x = sc.nextInt();
			
			if(n == 0 && x == 0){
				break;
			}
			
			int count = 0;
			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){
							count++;
						}
					}
				}
			}
			
			System.out.println(count);
		}
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) while (true) {
			final int n = sc.nextInt();
			final int x = sc.nextInt();
			
			if(n == 0 && x == 0){
				break;
			}
			
			int count = 0;
			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){
							count++;
						}
					}
				}
			}
			
			System.out.println(count);
		} true {
			final int n = sc.nextInt();
			final int x = sc.nextInt();
			
			if(n == 0 && x == 0){
				break;
			}
			
			int count = 0;
			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){
							count++;
						}
					}
				}
			}
			
			System.out.println(count);
		} final int n = sc.nextInt(); n sc.nextInt() sc.nextInt sc final 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;
			} break; int count = 0; count 0 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){
							count++;
						}
					}
				}
			} 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){
							count++;
						}
					}
				}
			} {
				for(int j = i + 1; j <= n; j++){
					for(int k = j + 1; k <= n; k++){
						if(i + j + k == x){
							count++;
						}
					}
				}
			} for(int j = i + 1; j <= n; 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 j n 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++ 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 sc = new Scanner(System.in);

		while (true) {
			final int n = sc.nextInt();
			final int x = sc.nextInt();
			
			if(n == 0 && x == 0){
				break;
			}
			
			int count = 0;
			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){
							count++;
						}
					}
				}
			}
			
			System.out.println(count);
		}
	}

} public class Main {
	
	public static void main(String args[]) {
		Scanner sc = new Scanner(System.in);

		while (true) {
			final int n = sc.nextInt();
			final int x = sc.nextInt();
			
			if(n == 0 && x == 0){
				break;
			}
			
			int count = 0;
			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){
							count++;
						}
					}
				}
			}
			
			System.out.println(count);
		}
	}

} Main
import java.util.Arrays;
import java.util.HashMap;
import java.util.Map;
import java.util.Scanner;

public class Main {
	
	public static void main(String args[]) {
		Scanner sc = new Scanner(System.in);

		while (true) {
			final int n = sc.nextInt();
			final int x = sc.nextInt();
			
			if(n == 0 && x == 0){
				break;
			}
			
			int count = 0;
			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){
							count++;
						}
					}
				}
			}
			
			System.out.println(count);
		}
	}

}