#include <bits/stdc++.h>
using namespace std;
long long a, b, c, l, tl, ans, ca, cb, cc;
long long min(long long a, long long b) { return a < b ? a : b; }
void cpy() {
  a = ca, b = cb;
  c = cc;
}
int main() {
  scanf("%lld%lld%lld%lld", &a, &b, &c, &l);
  ca = a;
  cb = b;
  cc = c;
  for (int i = l + 2; i >= 2; --i) ans += 1ll * i * (1ll * i - 1) / 2;
  if (b + c - a <= l) {
    if (a > b + c)
      tl = l;
    else
      tl = l - (b + c - a), a = b + c;
    for (int i = 0; i <= tl; ++i) {
      long long tb = min(a - b - c + 1ll * i, tl - 1ll * i);
      ans -= (tb + 1) * (tb + 2) / 2;
    }
  }
  cpy();
  if (a + b - c <= l) {
    if (c > a + b)
      tl = l;
    else
      tl = l - (a + b - c), c = a + b;
    for (int i = 0; i <= tl; ++i) {
      long long tb = min(c - a - b + i * 1ll, tl - i * 1ll);
      ans -= (tb + 1) * (tb + 2) / 2;
    }
  }
  cpy();
  if (a + c - b <= l) {
    if (b > a + c)
      tl = l;
    else
      tl = l - (a + c - b), b = a + c;
    for (int i = 0; i <= tl; ++i) {
      long long tb = min(b - a - c + i * 1ll, tl - i * 1ll);
      ans -= (tb + 1) * (tb + 2) / 2;
    }
  }
  printf("%lld", ans);
  return 0;
}
