06. Middle Characters

using System;
using System.Linq;

namespace MiddleCharacters
{
    class Program
    {
        static void Main(string[] args)
        {
            string str = Console.ReadLine();
            string output = MiddleCharacters(str);
            Console.WriteLine(output);
        }

        static string MiddleCharacters(string str)
        {
            string middle = "";

            int current = str.Length / 2;
            if (str.Length % 2 == 1)
            {
                middle += $"{ str[(char)current]}";
            }
            else
            {
                middle += $"{ str[(char)current - 1]}{ str[(char)current]}";
            }
            return middle;
        }
    }
}