import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.StringTokenizer;

public class Main {
  static InputReader in;
  static PrintWriter out;

  static class Solution {
    void solve() throws IOException {
      while (true) {
        int n = in.nextInt();
        int x = in.nextInt();
        int combination = 0;
        if (x == 0 && n == 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) {
                combination++;
              }
            }
          }
        }
        out.println(combination);
      }
      
//      End solve()
    }
//    End Solution
}

  public static void main(String[] args) throws IOException {
    in = new InputReader(System.in);
    out = new PrintWriter(System.out);
    Solution solver = new Solution();
    solver.solve();
    out.close();
}

  static class InputReader {
    public BufferedReader br;
    public StringTokenizer st;

    public InputReader(InputStream stream) {
      br = new BufferedReader(new InputStreamReader(stream));
    }

    public int nextInt() throws IOException {
      while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      }
      return Integer.parseInt(st.nextToken());
    }

    public long nextLong() throws IOException {
      while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      }
      return Long.parseLong(st.nextToken());
    }

    public String next() throws IOException {
      while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      }
      return st.nextToken();
    }

    public double nextDouble() throws IOException {
      while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      }
      return Double.parseDouble(st.nextToken());
    }


  }

} import java.io.BufferedReader; BufferedReader java.io import java.io.IOException; IOException java.io import java.io.InputStream; InputStream java.io import java.io.InputStreamReader; InputStreamReader java.io import java.io.PrintWriter; PrintWriter java.io import java.util.StringTokenizer; StringTokenizer java.util public class Main {
  static InputReader in;
  static PrintWriter out;

  static class Solution {
    void solve() throws IOException {
      while (true) {
        int n = in.nextInt();
        int x = in.nextInt();
        int combination = 0;
        if (x == 0 && n == 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) {
                combination++;
              }
            }
          }
        }
        out.println(combination);
      }
      
//      End solve()
    }
//    End Solution
}

  public static void main(String[] args) throws IOException {
    in = new InputReader(System.in);
    out = new PrintWriter(System.out);
    Solution solver = new Solution();
    solver.solve();
    out.close();
}

  static class InputReader {
    public BufferedReader br;
    public StringTokenizer st;

    public InputReader(InputStream stream) {
      br = new BufferedReader(new InputStreamReader(stream));
    }

    public int nextInt() throws IOException {
      while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      }
      return Integer.parseInt(st.nextToken());
    }

    public long nextLong() throws IOException {
      while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      }
      return Long.parseLong(st.nextToken());
    }

    public String next() throws IOException {
      while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      }
      return st.nextToken();
    }

    public double nextDouble() throws IOException {
      while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      }
      return Double.parseDouble(st.nextToken());
    }


  }

} Main static InputReader in; in static PrintWriter out; out public static void main(String[] args) throws IOException {
    in = new InputReader(System.in);
    out = new PrintWriter(System.out);
    Solution solver = new Solution();
    solver.solve();
    out.close();
} main {
    in = new InputReader(System.in);
    out = new PrintWriter(System.out);
    Solution solver = new Solution();
    solver.solve();
    out.close();
} in = new InputReader(System.in) in new InputReader(System.in) out = new PrintWriter(System.out) out new PrintWriter(System.out) Solution solver = new Solution(); solver new Solution() solver.solve() solver.solve solver out.close() out.close out String[] args args static class Solution {
    void solve() throws IOException {
      while (true) {
        int n = in.nextInt();
        int x = in.nextInt();
        int combination = 0;
        if (x == 0 && n == 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) {
                combination++;
              }
            }
          }
        }
        out.println(combination);
      }
      
//      End solve()
    }
//    End Solution
} Solution void solve() throws IOException {
      while (true) {
        int n = in.nextInt();
        int x = in.nextInt();
        int combination = 0;
        if (x == 0 && n == 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) {
                combination++;
              }
            }
          }
        }
        out.println(combination);
      }
      
//      End solve()
    } solve {
      while (true) {
        int n = in.nextInt();
        int x = in.nextInt();
        int combination = 0;
        if (x == 0 && n == 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) {
                combination++;
              }
            }
          }
        }
        out.println(combination);
      }
      
//      End solve()
    } while (true) {
        int n = in.nextInt();
        int x = in.nextInt();
        int combination = 0;
        if (x == 0 && n == 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) {
                combination++;
              }
            }
          }
        }
        out.println(combination);
      } true {
        int n = in.nextInt();
        int x = in.nextInt();
        int combination = 0;
        if (x == 0 && n == 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) {
                combination++;
              }
            }
          }
        }
        out.println(combination);
      } int n = in.nextInt(); n in.nextInt() in.nextInt in int x = in.nextInt(); x in.nextInt() in.nextInt in int combination = 0; combination 0 if (x == 0 && n == 0) {
          break;
        } x == 0 && n == 0 x == 0 x 0 n == 0 n 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) {
                combination++;
              }
            }
          }
        } 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) {
                combination++;
              }
            }
          }
        } {
          for (int j = i + 1; j <= n - 1; j++) {
            for (int k = j + 1; k <= n; k++){              
              if (i + j + k == x) {
                combination++;
              }
            }
          }
        } for (int j = i + 1; j <= n - 1; j++) {
            for (int k = j + 1; k <= n; k++){              
              if (i + j + k == x) {
                combination++;
              }
            }
          } 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) {
                combination++;
              }
            }
          } {
            for (int k = j + 1; k <= n; k++){              
              if (i + j + k == x) {
                combination++;
              }
            }
          } for (int k = j + 1; k <= n; k++){              
              if (i + j + k == x) {
                combination++;
              }
            } 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) {
                combination++;
              }
            } {              
              if (i + j + k == x) {
                combination++;
              }
            } if (i + j + k == x) {
                combination++;
              } i + j + k == x i + j + k i + j + k i j k x {
                combination++;
              } combination++ combination out.println(combination) out.println out combination static class InputReader {
    public BufferedReader br;
    public StringTokenizer st;

    public InputReader(InputStream stream) {
      br = new BufferedReader(new InputStreamReader(stream));
    }

    public int nextInt() throws IOException {
      while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      }
      return Integer.parseInt(st.nextToken());
    }

    public long nextLong() throws IOException {
      while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      }
      return Long.parseLong(st.nextToken());
    }

    public String next() throws IOException {
      while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      }
      return st.nextToken();
    }

    public double nextDouble() throws IOException {
      while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      }
      return Double.parseDouble(st.nextToken());
    }


  } InputReader public BufferedReader br; br public StringTokenizer st; st public InputReader(InputStream stream) {
      br = new BufferedReader(new InputStreamReader(stream));
    } InputReader {
      br = new BufferedReader(new InputStreamReader(stream));
    } br = new BufferedReader(new InputStreamReader(stream)) br new BufferedReader(new InputStreamReader(stream)) InputStream stream stream public int nextInt() throws IOException {
      while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      }
      return Integer.parseInt(st.nextToken());
    } nextInt {
      while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      }
      return Integer.parseInt(st.nextToken());
    } while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      } st == null || !st.hasMoreTokens() st == null st null !st.hasMoreTokens() st.hasMoreTokens() st.hasMoreTokens st {
        st = new StringTokenizer(br.readLine());
      } st = new StringTokenizer(br.readLine()) st new StringTokenizer(br.readLine()) return Integer.parseInt(st.nextToken()); Integer.parseInt(st.nextToken()) Integer.parseInt Integer st.nextToken() st.nextToken st public long nextLong() throws IOException {
      while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      }
      return Long.parseLong(st.nextToken());
    } nextLong {
      while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      }
      return Long.parseLong(st.nextToken());
    } while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      } st == null || !st.hasMoreTokens() st == null st null !st.hasMoreTokens() st.hasMoreTokens() st.hasMoreTokens st {
        st = new StringTokenizer(br.readLine());
      } st = new StringTokenizer(br.readLine()) st new StringTokenizer(br.readLine()) return Long.parseLong(st.nextToken()); Long.parseLong(st.nextToken()) Long.parseLong Long st.nextToken() st.nextToken st public String next() throws IOException {
      while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      }
      return st.nextToken();
    } next {
      while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      }
      return st.nextToken();
    } while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      } st == null || !st.hasMoreTokens() st == null st null !st.hasMoreTokens() st.hasMoreTokens() st.hasMoreTokens st {
        st = new StringTokenizer(br.readLine());
      } st = new StringTokenizer(br.readLine()) st new StringTokenizer(br.readLine()) return st.nextToken(); st.nextToken() st.nextToken st public double nextDouble() throws IOException {
      while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      }
      return Double.parseDouble(st.nextToken());
    } nextDouble {
      while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      }
      return Double.parseDouble(st.nextToken());
    } while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      } st == null || !st.hasMoreTokens() st == null st null !st.hasMoreTokens() st.hasMoreTokens() st.hasMoreTokens st {
        st = new StringTokenizer(br.readLine());
      } st = new StringTokenizer(br.readLine()) st new StringTokenizer(br.readLine()) return Double.parseDouble(st.nextToken()); Double.parseDouble(st.nextToken()) Double.parseDouble Double st.nextToken() st.nextToken st public class Main {
  static InputReader in;
  static PrintWriter out;

  static class Solution {
    void solve() throws IOException {
      while (true) {
        int n = in.nextInt();
        int x = in.nextInt();
        int combination = 0;
        if (x == 0 && n == 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) {
                combination++;
              }
            }
          }
        }
        out.println(combination);
      }
      
//      End solve()
    }
//    End Solution
}

  public static void main(String[] args) throws IOException {
    in = new InputReader(System.in);
    out = new PrintWriter(System.out);
    Solution solver = new Solution();
    solver.solve();
    out.close();
}

  static class InputReader {
    public BufferedReader br;
    public StringTokenizer st;

    public InputReader(InputStream stream) {
      br = new BufferedReader(new InputStreamReader(stream));
    }

    public int nextInt() throws IOException {
      while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      }
      return Integer.parseInt(st.nextToken());
    }

    public long nextLong() throws IOException {
      while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      }
      return Long.parseLong(st.nextToken());
    }

    public String next() throws IOException {
      while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      }
      return st.nextToken();
    }

    public double nextDouble() throws IOException {
      while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      }
      return Double.parseDouble(st.nextToken());
    }


  }

} public class Main {
  static InputReader in;
  static PrintWriter out;

  static class Solution {
    void solve() throws IOException {
      while (true) {
        int n = in.nextInt();
        int x = in.nextInt();
        int combination = 0;
        if (x == 0 && n == 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) {
                combination++;
              }
            }
          }
        }
        out.println(combination);
      }
      
//      End solve()
    }
//    End Solution
}

  public static void main(String[] args) throws IOException {
    in = new InputReader(System.in);
    out = new PrintWriter(System.out);
    Solution solver = new Solution();
    solver.solve();
    out.close();
}

  static class InputReader {
    public BufferedReader br;
    public StringTokenizer st;

    public InputReader(InputStream stream) {
      br = new BufferedReader(new InputStreamReader(stream));
    }

    public int nextInt() throws IOException {
      while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      }
      return Integer.parseInt(st.nextToken());
    }

    public long nextLong() throws IOException {
      while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      }
      return Long.parseLong(st.nextToken());
    }

    public String next() throws IOException {
      while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      }
      return st.nextToken();
    }

    public double nextDouble() throws IOException {
      while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      }
      return Double.parseDouble(st.nextToken());
    }


  }

} Main
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.StringTokenizer;

public class Main {
  static InputReader in;
  static PrintWriter out;

  static class Solution {
    void solve() throws IOException {
      while (true) {
        int n = in.nextInt();
        int x = in.nextInt();
        int combination = 0;
        if (x == 0 && n == 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) {
                combination++;
              }
            }
          }
        }
        out.println(combination);
      }
      
//      End solve()
    }
//    End Solution
}

  public static void main(String[] args) throws IOException {
    in = new InputReader(System.in);
    out = new PrintWriter(System.out);
    Solution solver = new Solution();
    solver.solve();
    out.close();
}

  static class InputReader {
    public BufferedReader br;
    public StringTokenizer st;

    public InputReader(InputStream stream) {
      br = new BufferedReader(new InputStreamReader(stream));
    }

    public int nextInt() throws IOException {
      while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      }
      return Integer.parseInt(st.nextToken());
    }

    public long nextLong() throws IOException {
      while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      }
      return Long.parseLong(st.nextToken());
    }

    public String next() throws IOException {
      while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      }
      return st.nextToken();
    }

    public double nextDouble() throws IOException {
      while (st == null || !st.hasMoreTokens()) {
        st = new StringTokenizer(br.readLine());
      }
      return Double.parseDouble(st.nextToken());
    }


  }

}