using System;

class BinToDec
{
    public static void Main(string[] args)
    {
        {
            Boolean validbinary;//creates object to validate binary number entered by user
            String bin_1;//creates object to store binary number
            String dec_1;//creates object to store decimal number
            Console.WriteLine("Welcome, to.....");
            Console.WriteLine("Binary to Decimal Conversion, Version 1.0");//Introduces program
            Console.WriteLine();//blank line
            Console.WriteLine("Please enter the positve binary number you wish to convert to decimal.");
            //requests input from user
            bin_1 = Console.ReadLine();//reads input and stores binary number
            try//will validate the number to verify its valid binary number (boolean)
            {
                dec_1 = Convert.ToInt64(bin_1, 2).ToString();//converts binary number to decimal
                validbinary = true;//if binary valid will go to "if" instructions below
            }
            catch//if binary not valid
            {
                dec_1 = "";//declares value of null to dec_1
                validbinary = false;//if binary not valid, go to "else" below
            }
            Console.WriteLine();//blank line
            if (validbinary == true)//from above, if binary valid, goes to this
            {
            Console.WriteLine("Your Binary Number of {0}", bin_1);//repeats users binary number
            Console.WriteLine("is equal to the Decimal Number {0}.", dec_1);//displays solution to user
            Console.WriteLine();//blank line
            Console.WriteLine();//blank line
            Console.WriteLine();//blank line
            Console.WriteLine("Thank You For Using Binary to Decimal Conversion.");//thanks user
            Console.WriteLine("Hit the Enter Key to Exit.");//instructs user to hit enter to end
            Console.ReadLine();//waits for input to end program
            }
            else//if binary not valid from above, goes to this
            {
            Console.WriteLine("*********************ERROR********************");//error message
            Console.WriteLine("***YOUR ENTRY IS NOT A VALID BINARY NUMBER!***");
            Console.WriteLine("****OR BINARY NUMBER ENTERED IS TOO LARGE!****");
            Console.WriteLine("*********************ERROR********************");
            Console.WriteLine();//blank line
            Console.WriteLine("Hit the Enter Key to Exit.");//instructs user to hit enter to end
            Console.ReadLine();//waits for input to end program
            }
        }
    }
}