using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace yuki_407
{
    class Program
    {
        static void Main(string[] args)
        {
            var k = new List<int>();
            long ans = 0;
            int max = 10000000 / 2;
            var z = new int[max];
            k.Add(2);
            for (int i = 3; i < max;i+=2)
            {
                bool t = true;
                for (int j = 3; j*j <=i; j++)
                {
                    if (i%j==0)
                    {
                        t = false;
                        break;
                    }
                    
                }
                if (t)
                {
                    k.Add(i);
                }
            }
            var a = scan();
            foreach (var i in k)
            {
                
                if (i*(a[0]-1)>a[1])
                {
                    break;
                }
                else
                {
                    int m = i * (a[0] - 1);
                    ans += a[1] - m + 1;
                }
            }
            Console.WriteLine(ans);
        }
        static int[] scan()
        {
            return
                Array.ConvertAll
                (Console.ReadLine().Split(' '), int.Parse);
        }
    }
}