Snowflake(ExamTask03)05.01.18

using System;
using System.Text.RegularExpressions;

namespace Snowflake
{
    class MainClass
    {
        public static void Main(string[] args)
        {
            string surface = @"^([^a-zA-Z0-9]+)$";
            string mantle = @"^([0-9_]+)$";
            string core = @"^([^\w]+)([\d_]+)([a-zA-Z]+)([\d_]+)([^\w]+)$";

            for (int i = 0; i < 1; i++)
            {
                string validSurface = Console.ReadLine();
                string validMantle = Console.ReadLine();
                string validCore = Console.ReadLine();
                string validMantleDup = Console.ReadLine();
                string validSurfaceDup = Console.ReadLine();

                if (Regex.IsMatch(validSurface, surface) && Regex.IsMatch(validMantle, mantle)
                    && Regex.IsMatch(validCore, core) && Regex.IsMatch(validMantleDup, mantle)
                    && Regex.IsMatch(validSurfaceDup, surface))
                {
                    Console.WriteLine("Valid");
                    string coreLen = Regex.Match(validCore, core).Groups[3].Value;
                    Console.WriteLine(coreLen.Length);
                }
                else
                {
                    Console.WriteLine("Invalid");
                }
            }
        }
    }
}