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

namespace _Substitute
{
    class Program
    {
        static void Main(string[] args)
        {
            int k = int.Parse(Console.ReadLine());
            int l = int.Parse(Console.ReadLine());
            int m = int.Parse(Console.ReadLine());
            int n = int.Parse(Console.ReadLine());
            string combination = string.Empty;

            int combinationCount = 0;
            while (combinationCount < 6)
            {
                for (int i = k; i <= 8; i++)
                {
                    for (int j = 9; j >= l; j--)
                    {
                        for (int b = m; b <= 8; b++)
                        {
                            for (int c = 9; c >= n; c--)
                            {
                                combination = $"{i}{j} - {b}{c}";
                                if (i % 2 == 0)
                                {
                                    if (j % 2 != 0)
                                    {
                                        if (b % 2 == 0)
                                        {
                                            if (c % 2 != 0)
                                            {

                                                if (i == b && j == c)
                                                {
                                                    Console.WriteLine("Cannot change the same player.");
                                                }
                                                else
                                                {
                                                    Console.WriteLine(combination);
                                                    combinationCount += 1;

                                                }
                                            }
                                        }
                                    }
                                }
                            }
                        }
                    }
                    break;
                }
            }
        }
    }
}