use proconio::input;

fn f(x: i32) -> i32{
    x*x*x-x*x+x+1
}

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

    let mut ans: i32 = 0;
    for n in a..=b{
        let mut ok: bool = true;
        for m in 2..n{
            if n%m == 0{
                ok = false;
            }
        }
        if ok{
            ans += f(n as i32);
        }
    }
    println!("{}", ans);
}