import java.util.Scanner;

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

		int way = 0;

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

			if(n == 0 && x == 0) {
				break;
			}

			way = 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) {
							way++;
						}
					}
				}
			}
			System.out.println(way);
		}

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

		int way = 0;

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

			if(n == 0 && x == 0) {
				break;
			}

			way = 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) {
							way++;
						}
					}
				}
			}
			System.out.println(way);
		}

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

		int way = 0;

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

			if(n == 0 && x == 0) {
				break;
			}

			way = 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) {
							way++;
						}
					}
				}
			}
			System.out.println(way);
		}

		scan.close();
	} main {
		Scanner scan = new Scanner(System.in);

		int way = 0;

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

			if(n == 0 && x == 0) {
				break;
			}

			way = 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) {
							way++;
						}
					}
				}
			}
			System.out.println(way);
		}

		scan.close();
	} Scanner scan = new Scanner(System.in); scan new Scanner(System.in) int way = 0; way 0 while(true) {
			int n = scan.nextInt();
			int x = scan.nextInt();

			if(n == 0 && x == 0) {
				break;
			}

			way = 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) {
							way++;
						}
					}
				}
			}
			System.out.println(way);
		} true {
			int n = scan.nextInt();
			int x = scan.nextInt();

			if(n == 0 && x == 0) {
				break;
			}

			way = 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) {
							way++;
						}
					}
				}
			}
			System.out.println(way);
		} int n = scan.nextInt(); n scan.nextInt() scan.nextInt scan int x = scan.nextInt(); x scan.nextInt() scan.nextInt scan if(n == 0 && x == 0) {
				break;
			} n == 0 && x == 0 n == 0 n 0 x == 0 x 0 {
				break;
			} break; way = 0 way 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) {
							way++;
						}
					}
				}
			} 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) {
							way++;
						}
					}
				}
			} {
				for(int j = i + 1; j <= n; j++) {
					for(int k = j + 1; k <= n; k++) {
						if(i + j + k == x) {
							way++;
						}
					}
				}
			} for(int j = i + 1; j <= n; j++) {
					for(int k = j + 1; k <= n; k++) {
						if(i + j + k == x) {
							way++;
						}
					}
				} 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) {
							way++;
						}
					}
				} {
					for(int k = j + 1; k <= n; k++) {
						if(i + j + k == x) {
							way++;
						}
					}
				} for(int k = j + 1; k <= n; k++) {
						if(i + j + k == x) {
							way++;
						}
					} 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) {
							way++;
						}
					} {
						if(i + j + k == x) {
							way++;
						}
					} if(i + j + k == x) {
							way++;
						} i + j + k == x i + j + k i + j + k i j k x {
							way++;
						} way++ way System.out.println(way) System.out.println System.out System System.out way scan.close() scan.close scan String[] args args public class Main {
	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);

		int way = 0;

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

			if(n == 0 && x == 0) {
				break;
			}

			way = 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) {
							way++;
						}
					}
				}
			}
			System.out.println(way);
		}

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

		int way = 0;

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

			if(n == 0 && x == 0) {
				break;
			}

			way = 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) {
							way++;
						}
					}
				}
			}
			System.out.println(way);
		}

		scan.close();
	}
} Main
import java.util.Scanner;

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

		int way = 0;

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

			if(n == 0 && x == 0) {
				break;
			}

			way = 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) {
							way++;
						}
					}
				}
			}
			System.out.println(way);
		}

		scan.close();
	}
}
