#![allow(unused)]
#![allow(non_snake_case)]
#![allow(dead_code)]

fn main() {
   let input_str = std::io::read_to_string(std::io::stdin()).unwrap();
   let mut input = input_str.split_whitespace();
   let mut read_int = ||->usize {input.next().unwrap().parse().unwrap()};
   
   let (A,B)=(read_int(),read_int());
   let primes = vec![2,3,5,7,11,13,17,19,23,29,31,37,41,43,47,53,59,61,67,71,73,79,83,89,97];
   let mut ans = 0;
   for &p in primes.iter(){
       if A <= p && p <= B{
           ans += (p*p*p-p*p+p+1);
       }
   }
   println!("{}",ans);
}