fn main() {
    let n = read::<i64>();
    let mut ans = 0;
    for x in 0..n + 1 {
        for y in 0..n + 1 {
            if x + y <= n {
                ans += 1;
            }
        }
    }
    println!("{}", ans);
}

fn read<T: std::str::FromStr>() -> T {
    let mut s = String::new();
    std::io::stdin().read_line(&mut s).ok();
    s.trim().parse().ok().unwrap()
}