using System;

    using System.Linq;          

public class Program

{

    public static void Main()

    {

        int[] PhoneNumber = new int[10];

string PhoneNumberText = "";

int SumPhone=0;

do{

Console.WriteLine("Enter your Phone Number:");

PhoneNumberText = Console.ReadLine();

if(PhoneNumberText.Length==10){

break;

}else{

Console.WriteLine("Your phone number is invalid digit, please enter numbers for 10 digits"+ 'A');

}

}while(true);

for(int i=0; i<PhoneNumberText.Length ; i++){

​

PhoneNumber[i]=Convert.ToInt32(PhoneNumberText[i])-48;

}

        SumPhone = PhoneNumber.Sum();

        Console.WriteLine(SumPhone);

if(SumPhone==9 || SumPhone==14) Console.WriteLine("ดีมาก");

else if(SumPhone==10 || SumPhone==13) Console.WriteLine("ปานกลาง");

else if(SumPhone==11 || SumPhone==12) Console.WriteLine("ไม่ดี");

else Console.WriteLine("ไม่พบคำตอบ");

    }

}