#include <bits/stdc++.h>
using namespace std;
const int inf = (int)1e9;
const int mod = inf + 7;
const double eps = 1e-9;
const double pi = acos(-1.0);
long long a, b, c, l;
long long ans;
int main() {
  ios_base::sync_with_stdio(0), cin.tie(0);
  cin >> a >> b >> c >> l;
  for (long long i = 0; i <= l; ++i) {
    ans += (l - i + 1) * (l - i + 2) / 2;
  }
  for (long long i = 0; i <= l; ++i) {
    if (i + a >= b + c) {
      long long cur = min(i, (i + a - b - c) / 2);
      ans -= (cur + 1) * (cur + 2) / 2;
    }
    if (i + b >= a + c) {
      long long cur = min(i, (i + b - a - c) / 2);
      ans -= (cur + 1) * (cur + 2) / 2;
    }
    if (i + c >= a + b) {
      long long cur = min(i, (i + c - b - a) / 2);
      ans -= (cur + 1) * (cur + 2) / 2;
    }
  }
  cout << ans << endl;
}
