Problem:
Score: 100 points

Problem Statement

Takahashi is solving quizzes. He has easily solved all but the last one.

The last quiz has three choices: 1, 2, and 3.

With his supernatural power, Takahashi has found out that the choices A and B are both wrong.

Print the correct choice for this problem.

Constraints

Each of the numbers A and B is 1, 2, or 3.

A and B are different.

Input

Input is given from Standard Input in the following format:

A
B

Output

Print the correct choice.

Sample Input 1

3
1

Sample Output 1

2

When we know 3 and 1 are both wrong, the correct choice is 2.

Sample Input 2

1
2

Sample Output 2

3

Solution in C# (Mono 4.6.2.0) (judge verdict: Accepted)

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

namespace ABC148A
{
    class Program
    {
        static void Main(string[] args)
        {
            HashSet<int> s = new HashSet<int>(){1,2,3};
            s.Remove(Cin.Int());
            s.Remove(Cin.Int());

            Console.WriteLine(s.First());
        }
    }

    class Solver
    {
        public Solver()
        {

        }

        public IConvertible Solve()
        {
            return 0;
        }
    }

    internal static class Cin
    {
        public static string String()
        {
            return Console.ReadLine();
        }

        public static int Int()
        {
            return int.Parse(String());
        }

        public static int[] IArr()
        {
            return Split().Select(int.Parse).ToArray();
        }

        public static long Long()
        {
            return long.Parse(String());
        }

        public static long[] LArr()
        {
            return Split().Select(long.Parse).ToArray();
        }

        public static double Double()
        {
            return double.Parse(String());
        }

        public static double[] DArr()
        {
            return Split().Select(double.Parse).ToArray();
        }

        private static IEnumerable<String> Split()
        {
            return String().Split(' ');
        }
    }
}