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

namespace tes
{
	class contest
	{
		static void Main(string[] args)
		{
			var num = Console.ReadLine().Split(' ').Select(int.Parse).ToArray();
            var dp = new bool[num[0]];
            dp[1] = true;
            int count = 0;

            for(int i = 1+num[1]; i<=1000000000; i+=num[1])
            {
                if (dp[i % num[0]] == true) break;
                else
                {
                    dp[i % num[0]] = true;
                    count++;
                }

            }
            Console.WriteLine(count);
            
		}

	}
}