#include <bits/stdc++.h>
using namespace std;
int main() {
  int a, b, c, l;
  cin >> a >> b >> c >> l;
  long long ans = 0;
  for (int i = 0; i <= l; i++) ans += 1LL * (i + 1) * (i + 2) / 2;
  int t = a - b - c;
  for (int i = 0; i <= l; i++) {
    int e = t + i;
    if (e < 0) continue;
    int yz = l - i;
    e = min(e, yz);
    ans -= 1LL * (e + 1) * (e + 2) / 2;
  }
  t = b - a - c;
  for (int i = 0; i <= l; i++) {
    int e = t + i;
    if (e < 0) continue;
    int yz = l - i;
    e = min(e, yz);
    ans -= 1LL * (e + 1) * (e + 2) / 2;
  }
  t = c - b - a;
  for (int i = 0; i <= l; i++) {
    int e = t + i;
    if (e < 0) continue;
    int yz = l - i;
    e = min(e, yz);
    ans -= 1LL * (e + 1) * (e + 2) / 2;
  }
  cout << ans << endl;
  return 0;
}
