[C# 퀴즈 풀이]숫자구분자변환

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

namespace number1
{
    class Program
    {
        static class Constants
        {
            public const bool DebugFlag = false;
        }

        static void D(string log)
        {
            if (Constants.DebugFlag) Console.WriteLine(log);
        }
        static void Main(string[] args)
        {
            if (args.Length != 1)
            {
                D("invalid arg");
                return;
            }
            string nu = args[0];
            nu = nu.Replace(',', ' ');
            nu = nu.Replace('.', ',');
            Console.WriteLine(nu);
        }
    }
}