#[macro_export]
macro_rules! setup {
    { mut $input:ident: SplitWhitespace $(,)? } => {
        use std::io::Read;
        let mut buf = String::new();
        std::io::stdin().read_to_string(&mut buf).unwrap();
        let mut $input = buf.split_whitespace();
    };
}

#[macro_export]
macro_rules! parse_next {
    ($str_iter:expr) => {
        $str_iter.next().unwrap().parse().unwrap()
    };
}

fn main() {
    setup! { mut input: SplitWhitespace };

    let n: usize = parse_next!(input);

    macro_rules! is_multiple {
        ($i:expr, $p:expr) => {
            $i != $p && $i % $p == 0
        };
    }

    let mut ps = vec![];
    for i in 2..=n {
        match i {
            i if is_multiple!(i, 2) => continue,
            i if is_multiple!(i, 3) => continue,
            i if is_multiple!(i, 5) => continue,
            i if is_multiple!(i, 7) => continue,
            i if is_multiple!(i, 11) => continue,
            i if is_multiple!(i, 13) => continue,
            i if is_multiple!(i, 17) => continue,
            i if is_multiple!(i, 19) => continue,
            i if is_multiple!(i, 23) => continue,
            i if is_multiple!(i, 29) => continue,
            i if is_multiple!(i, 31) => continue,
            i => ps.push(i),
        }
    }

    let ans: u64 = ps.into_iter().map(|p| p as u64).sum();

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