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

class Program
{
    public void Solve()
    {
        int[] AB = Console.ReadLine().Split(' ').Select(x => int.Parse(x)).ToArray();
        List<int> trip = Enumerable.Range(AB[0], AB[1] - AB[0] + 1).ToList();
        var contestAttend = 3;
        foreach (var contest in Enumerable.Range(23, 3))
        {
            contestAttend -= trip.Where(x => x == contest).Count();
        }
        Console.WriteLine(contestAttend);
    }

    static void Main()
    {
        var solver = new Program();
        solver.Solve();
    }
}