using System;
using System.Linq;
using System.IO;
using System.Text.RegularExpressions;
using System.Text;

namespace RenameMusicFiles
{
    class RenameMusicFiles
    {
        static void Main()
        {
            Console.WriteLine("Directory path:");
            string dir = Console.ReadLine();

            Console.WriteLine("Characters to remove from the front:");
            int cut = int.Parse(Console.ReadLine());

            string[] oldNames = Directory.GetFiles(dir);
            string[] newNames = new string[oldNames.Length];
            string newName;

            for (int i = 0; i < oldNames.Length; i++)
            {
                newName = Fix(oldNames[i].Substring(dir.Length + 1 + cut));
                newNames[i] = String.Concat(dir, "\\", newName);
            }

            for (int i = 0; i < oldNames.Length; i++)
            {
                File.Copy(oldNames[i], newNames[i]);
                File.Delete(oldNames[i]);
            }

            Console.WriteLine("Done");
        }

        private static string Fix(string p)
        {
            StringBuilder sb = new StringBuilder();
            foreach (var item in p)
            {
                if (item != '_')
                {
                    sb.Append(item);
                }
                else
                    sb.Append(' ');
            }
            return sb.ToString();
        }

    }
}