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

namespace Test
{
    class Program
    {
        static void Main(string[] args)
        {
            int[] x = Console.ReadLine().Split().Select(int.Parse).ToArray();
            if (x[0] < x[1])
            {
                Console.WriteLine((x[0] - 1) + (x[1] - x[0] - 1));
            }
            else
            {
                Console.WriteLine((2000000000 - x[0]) + (x[0] - x[1] - 1));
            }
        }
    }
}