import java.io.*;
import java.util.Arrays;

public class Main{
	public static void main(String[] args) throws IOException{ 
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		while(true){
			int count = 0;
			String line = br.readLine();
			String[] spl = line.split(" ");
			int n = Integer.parseInt(spl[0]);
			int x = Integer.parseInt(spl[1]);
			if(n == 0 && x == 0){break;}
			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.io.*; io.* java import java.util.Arrays; Arrays java.util public class Main{
	public static void main(String[] args) throws IOException{ 
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		while(true){
			int count = 0;
			String line = br.readLine();
			String[] spl = line.split(" ");
			int n = Integer.parseInt(spl[0]);
			int x = Integer.parseInt(spl[1]);
			if(n == 0 && x == 0){break;}
			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) throws IOException{ 
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		while(true){
			int count = 0;
			String line = br.readLine();
			String[] spl = line.split(" ");
			int n = Integer.parseInt(spl[0]);
			int x = Integer.parseInt(spl[1]);
			if(n == 0 && x == 0){break;}
			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 { 
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		while(true){
			int count = 0;
			String line = br.readLine();
			String[] spl = line.split(" ");
			int n = Integer.parseInt(spl[0]);
			int x = Integer.parseInt(spl[1]);
			if(n == 0 && x == 0){break;}
			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);
		}
	} BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); br new BufferedReader(new InputStreamReader(System.in)) while(true){
			int count = 0;
			String line = br.readLine();
			String[] spl = line.split(" ");
			int n = Integer.parseInt(spl[0]);
			int x = Integer.parseInt(spl[1]);
			if(n == 0 && x == 0){break;}
			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 count = 0;
			String line = br.readLine();
			String[] spl = line.split(" ");
			int n = Integer.parseInt(spl[0]);
			int x = Integer.parseInt(spl[1]);
			if(n == 0 && x == 0){break;}
			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 count = 0; count 0 String line = br.readLine(); line br.readLine() br.readLine br String[] spl = line.split(" "); spl line.split(" ") line.split line " " int n = Integer.parseInt(spl[0]); n Integer.parseInt(spl[0]) Integer.parseInt Integer spl[0] spl 0 int x = Integer.parseInt(spl[1]); x Integer.parseInt(spl[1]) Integer.parseInt Integer spl[1] spl 1 if(n == 0 && x == 0){break;} n == 0 && x == 0 n == 0 n 0 x == 0 x 0 {break;} break; 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++;
						}
					}
				}
			} 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++;
						}
					}
				} 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) throws IOException{ 
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		while(true){
			int count = 0;
			String line = br.readLine();
			String[] spl = line.split(" ");
			int n = Integer.parseInt(spl[0]);
			int x = Integer.parseInt(spl[1]);
			if(n == 0 && x == 0){break;}
			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) throws IOException{ 
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		while(true){
			int count = 0;
			String line = br.readLine();
			String[] spl = line.split(" ");
			int n = Integer.parseInt(spl[0]);
			int x = Integer.parseInt(spl[1]);
			if(n == 0 && x == 0){break;}
			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.io.*;
import java.util.Arrays;

public class Main{
	public static void main(String[] args) throws IOException{ 
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		while(true){
			int count = 0;
			String line = br.readLine();
			String[] spl = line.split(" ");
			int n = Integer.parseInt(spl[0]);
			int x = Integer.parseInt(spl[1]);
			if(n == 0 && x == 0){break;}
			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);
		}
	}
}