ExtractFile*-withSubstring()

using System;
using System.Text;

namespace ExtractFile
{
    class MainClass
    {
        public static void Main(string[] args)
        {
            string text = Console.ReadLine();
            int startIndexFileName = text.LastIndexOf('\\') + 1;
            int endIndexFileName = text.LastIndexOf('.');
            int fileNameLength = endIndexFileName - startIndexFileName;
            string fileName = text.Substring(startIndexFileName, fileNameLength);

            int startIndexExtension = text.LastIndexOf('.')+1;
            string extension = text.Substring(startIndexExtension);

            Console.WriteLine($"File name: {fileName}");
            Console.WriteLine($"File extension: {extension}");
        }
    }
}