#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  long r;
  while (cin >> n) {
    r = 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 >= 0 && d <= 1000) r++;
        }
      }
    }
    cout << r << endl;
  }
  return (0);
}
