Problem:
How many ways?

Write a program which identifies the number of combinations of three integers which satisfy the following conditions:

You should select three distinct integers from 1 to n.

A total sum of the three integers is x.

For example, there are two combinations for n = 5 and x = 9.

1 + 3 + 5 = 9

2 + 3 + 4 = 9

Input

The input consists of multiple datasets. For each dataset, two integers n and x are given in a line.

The input ends with two zeros for n and x respectively. Your program should not process for these terminal symbols.

Constraints

3 ≤ n ≤ 100

0 ≤ x ≤ 300

Output

For each dataset, print the number of combinations in a line.

Sample Input

5 9
0 0

Sample Output

2

Note

      解説

Solution in JAVA (judge verdict: Accepted)

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

public class Main{
	final static int MOD = 1000000007;
	final static int INF = 1000000000;

	public static void main(String[] args) throws IOException{
		NScanner sc = new NScanner(System.in);
		for(;;){
			int n = sc.nextInt();
			int x = sc.nextInt();
			if(n == 0 && x == 0)
				break;
			int cnt = 0;
			for(int i = 1; i <= n; ++i){
				for(int j = i+1; j <= n; ++j){
					if(i + j >= x) break;
					if(i + j < x - n) continue;
					for(int k = j+1; k <= n; ++k){
						if(i + j + k == x){
							++cnt; break;
						}
					}
				}
			}
			System.out.println(cnt);
		}
		
	}

}

class NScanner{

	private BufferedReader br;
	private StringTokenizer tok;

	public NScanner(InputStream is) throws IOException{
		br = new BufferedReader(new InputStreamReader(is));
		getLine();
	}

	private void getLine() throws IOException{
		while(tok == null || !hasNext()){
			tok = new StringTokenizer(br.readLine());
		}
	}

	private boolean hasNext(){
		return tok.hasMoreTokens();
	}

	public String next() throws IOException{
		if(hasNext()){
			return tok.nextToken();
		}else{
			getLine();
			return tok.nextToken();
		}
	}

	public int nextInt() throws IOException{
		if(hasNext()){
			return Integer.parseInt(tok.nextToken());
		}else{
			getLine();
			return Integer.parseInt(tok.nextToken());
		}
	}

	public long nextLong() throws IOException{
		if(hasNext()){
			return Long.parseLong(tok.nextToken());
		}else{
			getLine();
			return Long.parseLong(tok.nextToken());
		}
	}

	public double nextDouble() throws IOException{
		if(hasNext()){
			return Double.parseDouble(tok.nextToken());
		}else{
			getLine();
			return Double.parseDouble(tok.nextToken());
		}
	}
}