use proconio::input;

fn is_prime(n: usize) -> bool {
    n >= 2 && (2..n).all(|i| n % i != 0)
}

fn main() {
	input! {
		a: usize,
		b: usize,
	}

    let ans: usize = (a..=b)
        .filter(|x| is_prime(*x))
        .map(|x| x*x*x - x*x + x + 1)
        .sum();

	println!("{ans}");
}