#include <bits/stdc++.h>
using namespace std;
long long a, b, c;
long long n;
int main() {
  ios_base::sync_with_stdio(false);
  long long res = 0;
  cin >> a >> b >> c >> n;
  for (int i = 0; i <= n; ++i) {
    if ((a + i) < (b + c))
      continue;
    else {
      long long cc = min(i + a - b - c, n - i);
      res += (cc + 1) * (cc + 2) / 2;
    }
  }
  for (int i = 0; i <= n; ++i) {
    if ((b + i) < (a + c))
      continue;
    else {
      long long cc = min(i + b - a - c, n - i);
      res += (cc + 1) * (cc + 2) / 2;
    }
  }
  for (int i = 0; i <= n; ++i) {
    if ((c + i) < (a + b))
      continue;
    else {
      long long cc = min(i + c - b - a, n - i);
      res += (cc + 1) * (cc + 2) / 2;
    }
  }
  cout << (n + 1) * (n + 2) * (n + 3) / 6 - res;
}
