#include<iostream>
using namespace std;
int x[100][4001], n;
int main() {
	x[0][0] = 1;
	for (int i = 1; i < 10; i++) {
		for (int j = 0; j < 4000; j++) {
			for (int k = 0; k <= 1000; k++) {
				x[i][j + k] += x[i - 1][j];
			}
		}
	}
	int n;
	while (cin >> n) {
		cout << x[4][n] << endl;
	}
}