use proconio::input;
// use std::cmp;
//use std::collections::VecDeque;
// use std::collections::HashSet;

fn main() {
    input! {
        n: i32,
    }
    let mut result = 0; 
    for i in 1..n+1 {
        if i % 3 == 1 {
            result += i;
        } else if i % 3 == 2 {
            result += i.pow(2);
        } else if i % 3 == 0 {
            result += i.pow(20223);
        }
    }
    println!("{}", result)
}