using System;
using System.Linq;

namespace _632
{
    class Program
    {
        static void Main(string[] args)
        {
            string s = Console.ReadLine();
            int[] x = s.Replace("?","1").Split().Select(int.Parse).ToArray();
            int[] y = s.Replace("?","4").Split().Select(int.Parse).ToArray();
            if (x[1] == x.Max() || x[1] == x.Min()) Console.Write(1);
            if (y[1] == y.Max() || y[1] == y.Min()) Console.Write(4);
            Console.WriteLine();
        }
    }
}