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