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

namespace YukiCoder
{
    class Program
    {
        static void Main(string[] args)
        {
            var va = Console.ReadLine().Split().Select(int.Parse).ToArray();
            var vb = Enumerable.Range(va[0], va[1] - va[0] + 1);
            var nn  = vb.Where(x => 22 < x && x < 26).Count();
            Console.WriteLine(3-nn);
        }
    }
}