import java.util.Scanner;

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

		// ?????°??£?¨?
		int n = 0;
		int x = 0;
		int count = 0;

		while ( true ) {
			
			// ??\?????????
			n = sc.nextInt ();
			x = sc.nextInt ();

			if ( n == 0 && x == 0 ) {
				System.exit ( 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 );
			count = 0;
		}
	}
} import java.util.Scanner; Scanner java.util class Main {
	public static void main ( String[] args ) {
		Scanner sc = new Scanner ( System.in );

		// ?????°??£?¨?
		int n = 0;
		int x = 0;
		int count = 0;

		while ( true ) {
			
			// ??\?????????
			n = sc.nextInt ();
			x = sc.nextInt ();

			if ( n == 0 && x == 0 ) {
				System.exit ( 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 );
			count = 0;
		}
	}
} Main public static void main ( String[] args ) {
		Scanner sc = new Scanner ( System.in );

		// ?????°??£?¨?
		int n = 0;
		int x = 0;
		int count = 0;

		while ( true ) {
			
			// ??\?????????
			n = sc.nextInt ();
			x = sc.nextInt ();

			if ( n == 0 && x == 0 ) {
				System.exit ( 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 );
			count = 0;
		}
	} main {
		Scanner sc = new Scanner ( System.in );

		// ?????°??£?¨?
		int n = 0;
		int x = 0;
		int count = 0;

		while ( true ) {
			
			// ??\?????????
			n = sc.nextInt ();
			x = sc.nextInt ();

			if ( n == 0 && x == 0 ) {
				System.exit ( 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 );
			count = 0;
		}
	} Scanner sc = new Scanner ( System.in ); sc new Scanner ( System.in ) int n = 0; n 0 int x = 0; x 0 int count = 0; count 0 while ( true ) {
			
			// ??\?????????
			n = sc.nextInt ();
			x = sc.nextInt ();

			if ( n == 0 && x == 0 ) {
				System.exit ( 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 );
			count = 0;
		} true {
			
			// ??\?????????
			n = sc.nextInt ();
			x = sc.nextInt ();

			if ( n == 0 && x == 0 ) {
				System.exit ( 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 );
			count = 0;
		} n = sc.nextInt () n sc.nextInt () sc.nextInt sc x = sc.nextInt () x sc.nextInt () sc.nextInt sc if ( n == 0 && x == 0 ) {
				System.exit ( 0 );
			} n == 0 && x == 0 n == 0 n 0 x == 0 x 0 {
				System.exit ( 0 );
			} System.exit ( 0 ) System.exit System 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 count = 0 count 0 String[] args args
import java.util.Scanner;

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

		// ?????°??£?¨?
		int n = 0;
		int x = 0;
		int count = 0;

		while ( true ) {
			
			// ??\?????????
			n = sc.nextInt ();
			x = sc.nextInt ();

			if ( n == 0 && x == 0 ) {
				System.exit ( 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 );
			count = 0;
		}
	}
}