using System.Numerics;

public class Program
{
    public static void Main()
    {

        //BigInteger num = BigInteger.Parse(Console.ReadLine() ?? string.Empty);
        //int num = int.Parse(Console.ReadLine() ?? string.Empty);
        //string[] moji = (Console.ReadLine() ?? string.Empty).Trim().Split(' ');
        string str = Console.ReadLine() ?? string.Empty;
        string str2 = Console.ReadLine() ?? string.Empty;

        string ans = "";

        if(str.Length <= str2.Length)
        {
            for(int i = 0;i < str.Length;i++)
            {
                if (str[(str.Length-1)-i] =='1'&& str2[(str2.Length - 1) - i] == '1'|| str[(str.Length - 1) - i] == '0' && str2[(str2.Length - 1) - i] == '0')
                {
                    ans += "0";
                }
                else
                {
                    ans += "1";
                }
            }
            for(int i = str2.Length-str.Length-1;i >= 0;i--)
            {
                ans += str2[i];
            }

            str = "";
            for(int i = ans.Length-1; i >= 0;i--)
            {
                str+= ans[i];
            }
            int a = Convert.ToInt32(str,2);
            Console.WriteLine(a);
        }
        else
        {
            for (int i = 0; i < str2.Length; i++)
            {
                if (str[(str.Length - 1) - i] == '1' && str2[(str2.Length - 1) - i] == '1' || str[(str.Length - 1) - i] == '0' && str2[(str2.Length - 1) - i] == '0')
                {
                    ans += "0";
                }
                else
                {
                    ans += "1";
                }
            }
            for (int i = str.Length - str2.Length - 1; i >= 0; i--)
            {
                ans += str[i];
            }

            str = "";
            for (int i = ans.Length - 1; i >= 0; i--)
            {
                str += ans[i];
            }
            int a = Convert.ToInt32(str, 2);
            Console.WriteLine(a);

        }

    }
}