using System;

​

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Ingresa una cadena binaria: ");

        string s=Console.ReadLine();

        Console.WriteLine("Binario: "+s+"\nEl numero decimal es: "+x);  

    }

}

static class ExtensionStringConverter{

    public static double BinDec(this string s){

        int res=0;

        int x=0;

        for(int i=s.Length-1;i>=0; i--){

            if(s[i] == '1'){

                res+=(int) Math.Pow(2,i);

            }else if(s[i]=='0'){

                res+=-1;

                break;

            }

            x=(int)res;

        }

        return x;

    }

}

​