using System;
using static System.Console;
using System.Linq;
using System.Collections.Generic;

class Program
{
    static int NN => int.Parse(ReadLine());
    static int[] NList => ReadLine().Split().Select(int.Parse).ToArray();
    static int[][] NArr(long n) => Enumerable.Repeat(0, (int)n).Select(_ => NList).ToArray();
    public static void Main()
    {
        Solve();
    }
    static void Solve()
    {
        var n = ReadLine();
        var k = ReadLine();
        var n2 = (n[^1] - '0') % 2 == 0;
        var n3 = 0;
        for (var i = 0; i < n.Length; ++i) n3 += n[i] - '0';
        n3 %= 3;
        var k2 = (k[^1] - '0') % 2 == 0;
        // 123450
        // 285714
        if (n3 == 0)
        {
            if (n2) WriteLine(4);
            else WriteLine(5);
        }
        else if (n3 == 1)
        {
            if (n2) WriteLine(7);
            else WriteLine(2);
        }
        else
        {
            if (n2) WriteLine(k2 ? 7 : 8);
            else WriteLine(k2 ? 2 : 1);
        }
    }
}