class Program
{
    static void Main(string[] args)
    {
        string[] input = Console.ReadLine()!.Split(' ');
        int strat = int.Parse(input[0]);
        int end = int.Parse(input[1]);
        int count = 3;

        for (int i = strat; i <= end; i++)
        {
            if (i == 23 || i == 24 || i == 25)
            {
                count--;
            }
        }

        Console.WriteLine(count);
    }
}