#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  while (cin >> n) {
    long long cnt = 0;
    for (int a = 0; a < 1001; a++) {
      if (a > n) break;
      for (int b = 0; b < 1001; b++) {
        if (a + b > n) break;
        cnt += n - a - b + 1;
      }
    }
    cout << cnt << endl;
  }
}
