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

namespace ConsoleApplication23
{
    class Program
    {
        static int divides (int num1, int num2)
        {
            int min, divider, lowest = -1;
            min = Math.Min(num1, num2);
            divider = min;
            while (divider > 2)
            {
                divider -= 1;
                if (num2 % divider == 0 && num2 % divider == 0)
                    lowest = divider;
            }
            return lowest;
        }
        static void Main(string[] args)
        {
            int num1, num2, divider;
            num1 = int.Parse(Console.ReadLine());
            num2 = int.Parse(Console.ReadLine());
            divider = divides(num1, num2);
            Console.WriteLine(divider);
        }
    }
}