fn main() {
    let mut n = String::new();
    std::io::stdin().read_line(&mut n).ok();
    let n: usize = n.trim().parse().unwrap();

    let mut result = 0usize;
    for i in 0..=n {
        for j in 0..=n {
            if i + j > n { break; }
            result += 1;
        }
    }

    println!("{}", result);
}