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 a = scan();
            int max = a[1]/(a[0]-1);
           
            var p = new List<int>();
            if (max>1)
            {
                eratos(p, max);
            }
            long ans = 0;
            foreach (var i in p)
            {
                int m = a[1] - i*(a[0]-1) + 1;
                if (m<=0)
                {
                    break;
                }
                else
                {
                    ans += m;
                }
            }
            Console.WriteLine(ans);
        }
        
        //2～nまでの素数のリスト(n>=2)
        static void eratos(List<int> Prime,int n)
        {
            var a = new bool[n+1];
            a[0] =a[1]= true;
            int i;
            for (i = 2; i*i<=n; i++)
            {
                if (!a[i])
                {
                    Prime.Add(i);
                    int j = i << 1;
                    while (j <= n)
                    {
                        a[j] = true;
                        j = j + i;
                    }
                }    
            }
            for (; i <=n ; i++)if(!a[i])Prime.Add(i);          
        }
        static int[] scan()
        {
            return
                Array.ConvertAll
                (Console.ReadLine().Split(' '), int.Parse);
        }
    }
}