// #Sazaの1日1AC
#include <bits/stdc++.h>
using namespace std;
const long long mod = 1000000000 + 7;
const long long INF = 9e18;
const double PI = 3.14159265358979323846;

//マクロ
//型エイリアス
using ll = long long;
using P = pair<long long, long long>;
using vl = vector<long long>;
using vvl = vector<vector<long long>>;
using vP = vector<pair<long long, long long>>;
//ショートカット
#define rep(i, n) for (int i = 0; i < n; i++)
#define rep2(i, k, n) for (int i = k; i < n; i++) //半開区間
#define all(v) v.begin(), v.end()
#define rall(v) v.rbegin(), v.rend()
#define pb push_back
#define mkp make_pair
//入力
#define vin(v, N)                   \
  for (long long i = 0; i < N; i++) \
  cin >> v.at(i)
#define lin(n) \
  long long n; \
  cin >> n
#define chin(x) \
  char x;       \
  cin >> x;
#define sin(s) \
  string s;    \
  cin >> s;
#define vlin(v, N)                  \
  vector<long long> v(N);           \
  for (long long i = 0; i < N; i++) \
  cin >> v.at(i)

#define max(a, b) max((ll)a, (ll)b)
#define min(a, b) min((ll)a, (ll)b)

//関数
//最大公約数
long long gcd(long long m, long long n)
{
  long long a = max(m, n);
  long long b = min(m, n);
  long long r = a % b;
  while (r != 0)
  {
    a = b;
    b = r;
    r = a % b;
  }
  return b;
}
// 最小公倍数
long long lcd(long long m, long long n)
{
  return m * n / gcd(m, n);
}
//xのn乗
long long power(long long x, long long N)
{
  long long ret = 1;
  for (long long i = 0; i < N; i++)
    ret *= x;
  return ret;
}
//繰り返し二乗法
long long repeat_squaring(long long x, long long n)
{
  if (n == 0)
    return 1;
  else if (n % 2 == 0)
  {
    long long t = repeat_squaring(x, n / 2);
    return t * t % mod;
  }
  else
    return x * repeat_squaring(x, n - 1);
}
//素因数分解(mapで返す)
map<long long, long long> factor(long long p)
{
  ll p1 = p;
  map<long long, long long> ret;
  for (long long i = 2; i * i <= p1; i++)
  {
    while (p % i == 0)
    {
      ret[i]++;
      p /= i;
    }
  }
  if (p != 1)
    ret[p]++;
  return ret;
}
//素数判定
bool is_prime(long long N)
{
  for (long long i = 2; i * i <= N; i++)
  {
    if (N % i == 0)
      return false;
  }
  return true;
}
//最大値更新
void chmax(long long &a, long long b)
{
  a = max(a, b);
}
//最小値更新
void chmin(long long &a, long long b)
{
  a = min(a, b);
}

//構造体
//Union-Find木
struct UnionFind
{
  //メンバ変数
  vector<long long> par; //par[i]:=頂点iの親
  vector<long long> s;   //s[i]:=頂点iが属する集合の個数(iが根のとき)

  //コンストラクタ
  UnionFind(long long N) : par(N), s(N)
  {
    for (long long i = 0; i < N; i++)
    {
      par[i] = i; //最初はすべてが根として初期化
      s[i] = 1;
    }
  }
  //メンバ関数
  //root(i):=頂点iの根
  long long root(long long i)
  {
    if (par[i] == i)
      return i;
    par[i] = root(par[i]); //経路圧縮
    return root(par[i]);   //再帰
  }
  //size[i]:=iが属する集合の個数
  long long size(long long i)
  {
    return s[root(i)];
  }
  //same(x,y) xとyが同じ根を持つか(同じ集合に含まれるか)
  bool same(long long x, long long y)
  {
    return root(x) == root(y);
  }
  //unite(x,y) xの根をyの根に繋げる(集合を合併)
  void unite(long long x, long long y)
  {
    if (!same(x, y))
    {
      long long rx = root(x);
      long long ry = root(y);
      par[rx] = par[ry];
      s[ry] = s[rx] + s[ry];
    }
  }
};
//Binary Indexed Tree
struct BIT
{
  vector<long long> bit;
  long long N;

  BIT(long long n)
  {
    N = n;
    bit.resize(N + 1);
  }

  void add(long long i, long long w)
  {
    for (long long x = i; x <= N; x += x & -x)
    {
      bit[x] += w;
    }
  }
  long long sum(long long i)
  {
    long long ret = 0;
    for (long long x = i; x > 0; x -= x & -x)
    {
      ret += bit[x];
    }
    return ret;
  }
};

/////////////////⊂('ω'⊂ )))Σ≡GO!/////////////////

//メイン関数
int main()
{
  //doubleの桁数
  cout << fixed << setprecision(10);

  while (true)
  {
    lin(N);
    lin(x);
    if(N == 0 && x == 0) break;
    ll res = 0;
    for (int i = 1; i <= N; i++)
    {
      for (int j = i + 1; j <= N; j++)
      {
        int k = x - i - j;
        if (1 <= k && k <= N && i < k && j < k)
          res++;
      }
    }

    cout << res << endl;
  }
}


Measured memory_bytes: 3108