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



class Program
{
    public void Proc()
    {
        Reader.IsDebug = false;
        long[] inpt = Reader.ReadLine().Split(' ').Select(a=>long.Parse(a)).ToArray();
        Dictionary<long, bool> dic = new Dictionary<long, bool>();

        long pos = 0;
        long ans = 0;
        dic.Add(0, true);
        for(long i=0; i<inpt[0]; i++) {
            pos = (pos + inpt[1]) % inpt[0];
            if(dic.ContainsKey(pos)) {
               break; 
            }
            dic.Add(pos, true);
            ans++;
        }
        Console.WriteLine(ans);
    }



    public class Reader
    {
        public static bool IsDebug = true;
        private static String PlainInput = @"

5 2





";
        private static System.IO.StringReader Sr = null;
        public static string ReadLine()
        {
            if (IsDebug)
            {
                if (Sr == null)
                {
                    Sr = new System.IO.StringReader(PlainInput.Trim());
                }
                return Sr.ReadLine();
            }
            else
            {
                return Console.ReadLine();
            }
        }
    }
    static void Main()
    {
        Program prg = new Program();
        prg.Proc();
    }
}