#include <bits/stdc++.h>
using namespace std;
int a, b, c, d, n;
int ans;
int main() {
  while (cin >> n) {
    int m = min(1000, n);
    ans = 0;
    for (a = 0; a <= m; a++) {
      for (b = 0; a + b <= m; b++) {
        for (c = 0; a + b + c <= m; c++) {
          if (n - a - b - c <= 1000) ans++;
        }
      }
    }
    cout << ans << endl;
  }
  return 0;
}
