import java.io.*;
class Main {
public static void main(String[] args) throws Exception {
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
long n = Integer.parseInt(br.readLine()); // long사용해야함
long result = n * (n + 1) * (2 * n + 1) / 6; // 공식
System.out.println(result);
}
}