using System;

class Program
{
    static bool IsPrime(int n)
    {
        if (n < 2) return false;
        for (int i = 2; i * i <= n; i++)
            if (n % i == 0) return false;
        return true;
    }

    static void Main()
    {
        var inp = Array.ConvertAll(Console.ReadLine().Split(), int.Parse);
        int A = inp[0], B = inp[1];
        long sum = 0;

        for (int x = A; x <= B; x++)
        {
            if (IsPrime(x))
            {
                long fx = (long)x * x * x - (long)x * x + x + 1;
                sum += fx;
            }
        }

        Console.WriteLine(sum);
    }
}