use proconio::input;

fn main() {
    input! {
        n: i64,
    }

    let m = (n as f64).sqrt() as usize + 1;
    let mut is_primes = vec![true; m];
    is_primes[0] = false;
    is_primes[1] = false;
    for diviser in 2..m {
        if !is_primes[diviser] {
            continue;
        }
        for kd in (2 * diviser..m).step_by(diviser) {
            is_primes[kd] = false;
        }
    }

    println!(
        "{}",
        (2..m)
            .filter(|&i| is_primes[i])
            .map(|i| (2..)
                .map(|k| (i as i64).pow(k))
                .take_while(|&v| v <= n)
                .sum::<i64>())
            .sum::<i64>()
    );
}