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

class Main {

    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        while(true){
            StringTokenizer st=new StringTokenizer(br.readLine());
            int n=Integer.parseInt(st.nextToken());
            int x=Integer.parseInt(st.nextToken());
            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.io.*; io.* java import java.util.*; util.* java class Main {

    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        while(true){
            StringTokenizer st=new StringTokenizer(br.readLine());
            int n=Integer.parseInt(st.nextToken());
            int x=Integer.parseInt(st.nextToken());
            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) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        while(true){
            StringTokenizer st=new StringTokenizer(br.readLine());
            int n=Integer.parseInt(st.nextToken());
            int x=Integer.parseInt(st.nextToken());
            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 {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        while(true){
            StringTokenizer st=new StringTokenizer(br.readLine());
            int n=Integer.parseInt(st.nextToken());
            int x=Integer.parseInt(st.nextToken());
            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);
        }
        
    } BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); br new BufferedReader(new InputStreamReader(System.in)) while(true){
            StringTokenizer st=new StringTokenizer(br.readLine());
            int n=Integer.parseInt(st.nextToken());
            int x=Integer.parseInt(st.nextToken());
            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 {
            StringTokenizer st=new StringTokenizer(br.readLine());
            int n=Integer.parseInt(st.nextToken());
            int x=Integer.parseInt(st.nextToken());
            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);
        } StringTokenizer st=new StringTokenizer(br.readLine()); st new StringTokenizer(br.readLine()) int n=Integer.parseInt(st.nextToken()); n Integer.parseInt(st.nextToken()) Integer.parseInt Integer st.nextToken() st.nextToken st int x=Integer.parseInt(st.nextToken()); x Integer.parseInt(st.nextToken()) Integer.parseInt Integer st.nextToken() st.nextToken st if(n==0&&x==0) break; n==0&&x==0 n==0 n 0 x==0 x 0 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 System.out.println(count) System.out.println System.out System System.out count String[] args args
import java.io.*;
import java.util.*;

class Main {

    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        while(true){
            StringTokenizer st=new StringTokenizer(br.readLine());
            int n=Integer.parseInt(st.nextToken());
            int x=Integer.parseInt(st.nextToken());
            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);
        }
        
    }
}