#include<iostream>
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;
}