using System;

using System.Text.RegularExpressions;

public class Program

{

    public static void Main()

    {

        string no = "08709079777";

        Console.WriteLine(ConvertStringToInt32(no));

        Console.WriteLine("Hello World");

    }

    private static Int64 ConvertStringToInt32(string number)

    {

        Int64 returnIntVal = 0;

        try

        {

            if (!string.IsNullOrEmpty(number))

            {

                var cleanNumber = Regex.Replace(number, @"\s+", "");

                Console.WriteLine(cleanNumber);

                if (Int64.TryParse(cleanNumber, out Int64 ux))

                {

                    Console.WriteLine(ux);

                    returnIntVal = ux;

                }

                else

                {

                    Console.WriteLine("Else block");

                }

            }

            else

            {

                returnIntVal = 0;

            }

        }

        catch(Exception exp)

        {

            var ex = exp;

        }

        Console.WriteLine("returnIntVal: " + returnIntVal);

        return returnIntVal;

    }

}