fn get_primes(lim: usize) -> Vec<usize> {
    if lim == 0 { return vec![]; }
    let mut flg: Vec<bool> = vec![true; lim+1];
    flg[0] = false;
    flg[1] = false;
    for i in 2..=((lim as f64).sqrt().ceil() as usize) {
        if !flg[i] { continue; }
        (i*i..=lim).step_by(i).for_each(|j| { flg[j] = false; });
    }
    flg.iter().enumerate().filter(|pair| *pair.1).map(|pair| pair.0).collect()
}

fn main() {
    let mut nl = String::new();
    std::io::stdin().read_line(&mut nl).ok();
    let nl: Vec<usize> = nl.trim().split_whitespace().map(|s| s.parse().unwrap()).collect();
    let n = nl[0];
    let l = nl[1];

    let lim = l / (n-1);
    let result: usize = get_primes(lim).iter()
        .map(|p| l - (n-1) * p + 1)
        .sum();
    println!("{}", result);
}